Slow Cooker Steak and Caramelized Onion Breakfast Sandwich

Name: Slow Cooker Steak and Caramelized Onion Breakfast Sandwich
Prep time: 15 min
Cook time: 6 h
Total time: 6 h 15 min
Yield: 4 servings
Cuisine: American
Ingredients: 1½ lbs (680 g) Beef steak (flank, skirt, or ribeye), thinly sliced (about 1/4 inch thick), cutting across the grain; 3 large (600 g) Yellow onions, thinly sliced into rings; 2 tbsp (30 g) Unsalted butter, for greasing slow cooker; 1 cup (240 ml) Beef broth or beef stock; 8 slices (225 g) Provolone cheese slices; 4 rolls (440 g) Hoagie rolls or crusty sandwich rolls; 3 cloves (12 g) Garlic cloves, minced; 3 sprigs (3 g) Fresh thyme sprigs (or 1 teaspoon dried thyme) (optional); 1 tbsp (15 ml) Worcestershire sauce; Salt, to taste; Black pepper, freshly ground, to taste; ½ cup (120 ml) Dry red wine (optional); 1 tsp (5 ml) Olive oil or vegetable oil, for browning steak (optional)

From the MyKitchenBank Kitchen

Tender beef steak slow-cooked for hours with onions until they transform into silky, deeply caramelized strands, then piled onto crusty hoagie rolls with melted provolone cheese. This recipe is best prepared the evening before for overnight cooking, or made completely ahead and reheated, making it perfect for a leisurely breakfast or brunch. Despite its simplicity, the flavors are rich and complex—the beef shreds at the touch of a fork, and the onions are sweet and glossy from hours of gentle heat.

Prep: 15 min
Cook: 6 hr
Total: 6 hr 15 min
Makes: 4 breakfast sandwiches

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Ingredients

4 servings

1½ lbs (680 g) Beef steak (flank, skirt, or ribeye), thinly sliced (about 1/4 inch thick), cutting across the grain
3 large (600 g) Yellow onions, thinly sliced into rings
2 tbsp (30 g) Unsalted butter, for greasing slow cooker
1 cup (240 ml) Beef broth or beef stock
8 slices (225 g) Provolone cheese slices
4 rolls (440 g) Hoagie rolls or crusty sandwich rolls
3 cloves (12 g) Garlic cloves, minced
3 sprigs (3 g) Fresh thyme sprigs (or 1 teaspoon dried thyme) (optional)
1 tbsp (15 ml) Worcestershire sauce
Salt, to taste
Black pepper, freshly ground, to taste
½ cup (120 ml) Dry red wine (optional)
1 tsp (5 ml) Olive oil or vegetable oil, for browning steak (optional)

Equipment (6)

4–6 quart slow cooker
Cutting board and sharp knife
Large skillet (optional, for browning steak)
Tongs or wooden spoon
Forks or sturdy spoon for shredding
Toaster oven or broiler (for toasting rolls)

Steps

Before you start

This recipe requires 6–8 hours of slow cooking on low (or 3–4 hours on high); plan to start in the morning for dinner or overnight for brunch.
Partially freeze the beef for 30–45 minutes before slicing to get thin, clean cuts.
Use a tough, less expensive cut like flank, skirt, or chuck that becomes tender during slow cooking—not a premium steak.
If browning the steak (optional but recommended), have a large skillet ready.

1
Prepare ingredients
- Slice the beef steak about 1/4 inch thick, cutting across the grain for maximum tenderness.
- Slice the onions into thin rings, about 1/4 inch thick.
- Mince the 3 garlic cloves.
- If using fresh thyme, strip the leaves from the stems and discard the stems.
- Set everything aside on your cutting board.
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Tip: Partially freeze the steak for 30–45 minutes before slicing to make thin, clean cuts—it will thaw during cooking and shred beautifully.
2
Brown steak (optional)Oven 375°F / 190°C
- If desired for extra depth of flavor, heat 1 teaspoon oil in a large skillet over medium-high heat (about 375°F / 190°C).
- Working in two batches to avoid crowding, add steak slices in a single layer and sear for 1–2 minutes per side until lightly browned; the meat should still be raw inside.
- Transfer to a clean plate.
- This step adds flavor but can be skipped if time is limited.
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Ready when: Steak is lightly browned on both sides but still raw inside
Tip: Don't crowd the pan—brown in batches for even caramelization. Overcrowding steams the meat instead of browning it.
3
Layer ingredients in slow cooker
- Rub the inside of your 4–6 quart slow cooker with the butter.
- Add half the sliced onions in an even layer on the bottom.
- Spread the beef steak (browned or raw) over the onions.
- Sprinkle the minced garlic over the beef.
- Add the fresh thyme sprigs (or 1 teaspoon of dried thyme if fresh is unavailable).
- Pour the beef broth and red wine (if using) over everything.
- Add the 1 tablespoon of Worcestershire sauce.
- Season generously with salt and pepper to taste.
- Top with the remaining onion slices, spreading them in an even layer.
4
Slow cook on low
- Cover the slow cooker and cook on LOW for 6 to 8 hours (or on HIGH for 3 to 4 hours if you're short on time).
- The beef and onions are done when the beef shreds easily with a fork and the onions are deeply caramelized, a silky golden-brown color, and completely tender.
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Ready when: Beef shreds easily with a fork and onions are deeply caramelized, silky, and completely tender
Tip: Resist the urge to lift the lid—each time you open it, you add 15–20 minutes to the cooking time. Trust the slow cooker; you'll be rewarded.
5
Shred beef and season
- Carefully remove the slow cooker lid (the steam is hot).
- Remove and discard the thyme sprigs.
- Using two forks or a sturdy spoon, shred the beef directly in the cooker, breaking it into bite-sized pieces.
- Stir well to combine the shredded beef, caramelized onions, and cooking liquid.
- Taste a spoonful and add more salt and pepper as needed.
- The mixture should taste savory and well-seasoned.
6
Toast rolls and assembleOven 200°F / 95°C
- Split each hoagie roll open lengthwise.
- Optionally, place the split rolls cut-side up in a toaster oven or under a broiler for 1–2 minutes until lightly golden and crispy (watch carefully to prevent burning).
- Spoon about 3/4 to 1 cup of the warm shredded beef and onion mixture onto the bottom half of each roll.
- Lay 1–2 slices of provolone cheese on top of the beef.
- Close the sandwich with the top roll.
- The residual heat will soften the cheese slightly; if you prefer it fully melted, wrap the assembled sandwich loosely in foil and place in a warm 200°F (93°C) oven for 1–2 minutes.
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Ready when: Rolls are lightly toasted; cheese is warm and softened
Tip: If the beef mixture cools down while you're assembling, reheat it gently in a skillet over medium heat or in the microwave for 1–2 minutes.

Good to know

Tips

Slice the steak thin: Partially freeze the beef for 30–45 minutes before slicing to make thin, clean cuts that will shred beautifully.
Don't peek: Resist opening the slow cooker lid frequently; each opening adds 15–20 minutes to cooking time.
Make it fancy: Toast the rolls and layer the sandwich with fresh arugula, tomato slices, or pickled peppers for brightness and texture.
Reheat efficiently: If the beef-onion mixture cools while you're assembling, briefly reheat it in a skillet over medium heat or the microwave (1–2 minutes) before serving.

Make ahead

Fully prepare this recipe the day before—it keeps in the refrigerator for up to 4 days—then gently reheat the beef-onion mixture and assemble fresh sandwiches in the morning for a quick breakfast. Alternatively, prep and layer the slow cooker the evening before, refrigerate the insert overnight, and start cooking in the morning for ready-to-eat sandwiches by afternoon.

Storage & reheating

Refrigerator: Store the shredded beef and onion mixture (without the bread) in an airtight container for up to 4 days. Reheat gently in a skillet over medium heat, stirring occasionally, or in the microwave on medium power for 2–3 minutes. Room temperature: The assembled sandwich is best eaten fresh but can be loosely wrapped for up to 2 hours. Freezer: Freeze the beef-onion mixture in an airtight container for up to 3 months; thaw overnight in the refrigerator and reheat as directed.

Substitutions

Beef steak (flank, skirt, or ribeye) → Chuck roast, brisket, or any tough cut that becomes tender when slow-cooked. Adjust slicing thickness and cooking time if using a much tougher cut. Flank and skirt steak are ideal alternatives.
Provolone cheese slices → Swiss, aged cheddar, pepper jack, or American cheese. Each brings a different flavor profile; use the same weight or number of slices.
Beef broth or beef stock → Vegetable broth, chicken broth, or replace half with additional red wine. You need about 1 cup of liquid total; adjust proportions to taste.
Dry red wine → Dry white wine, balsamic vinegar, or simply omit and increase broth to 1.5 cups. Omitting gives a cleaner beef flavor; white wine adds brightness.