Slow Cooker Green Lentils with Mushrooms, Leeks and Thyme

Name: Slow Cooker Green Lentils with Mushrooms, Leeks and Thyme
Prep time: 15 min
Total time: 15 min
Yield: 4 servings
Cuisine: French
Ingredients: 1½ cups (300 g) green lentils (lentilles du Puy or French green lentils), rinsed and picked over; 8 oz (225 g) cremini or baby bella mushrooms, cleaned, quartered; 2 medium (280 g) leeks, white and light green parts, halved lengthwise, rinsed, sliced into half-moons; 3 cloves (15 g) garlic cloves, minced; 3½ cups (840 ml) low-sodium vegetable broth; ½ cup (120 ml) dry white wine (such as Sauvignon Blanc); 4 sprigs (8 g) fresh thyme sprigs; 1 whole bay leaf; 2 tablespoons (30 ml) extra-virgin olive oil; ¾ teaspoon (4½ g) kosher salt; ¼ teaspoon (½ g) freshly ground black pepper; 1 tablespoon (15 g) Dijon mustard (optional); 2 tablespoons (8 g) fresh flat-leaf parsley, chopped, finely chopped (optional)

From the MyKitchenBank Kitchen

A rustic French-inspired braise of tender green lentils studded with earthy mushrooms and sweet leeks, infused with fresh thyme. This hands-off slow cooker dish is rich enough to serve as a vegetarian main or a refined side to roasted chicken or fish. The lentils stay intact and don't turn mushy, while the vegetables meld into the cooking liquid to create a silky, savory sauce.

Prep: 15 min
Cook: —
Wait: 6 hr
Total: 6 hr 15 min
Makes: About 4 cups (1 L), serves 4 as a side or light main

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Ingredients

4 servings

1½ cups (300 g) green lentils (lentilles du Puy or French green lentils), rinsed and picked over
8 oz (225 g) cremini or baby bella mushrooms, cleaned, quartered
2 medium (280 g) leeks, white and light green parts, halved lengthwise, rinsed, sliced into half-moons
3 cloves (15 g) garlic cloves, minced
3½ cups (840 ml) low-sodium vegetable broth
½ cup (120 ml) dry white wine (such as Sauvignon Blanc)
4 sprigs (8 g) fresh thyme sprigs
1 whole bay leaf
2 tablespoons (30 ml) extra-virgin olive oil
¾ teaspoon (4.5 g) kosher salt
¼ teaspoon (0.5 g) freshly ground black pepper
1 tablespoon (15 g) Dijon mustard (optional)
2 tablespoons (8 g) fresh flat-leaf parsley, chopped, finely chopped (optional)

Equipment (5)

6-quart (5.7 L) slow cooker
Colander
Chef's knife
Cutting board
Wooden spoon

Steps

Before you start

Rinse the green lentils under cold water and pick through to remove any stones or debris
Cut the leeks in half lengthwise, rinse thoroughly between layers to remove any grit, then slice into half-moons
Clean the mushrooms with a damp cloth and cut into quarters

1
Combine all ingredients in slow cooker
- Place the rinsed green lentils, quartered mushrooms, sliced leeks, and minced garlic into a 6-quart slow cooker.
- Pour in the vegetable broth and dry white wine.
- Add the thyme sprigs, bay leaf, olive oil, kosher salt, and black pepper.
- Stir gently with a wooden spoon to combine evenly.
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Tip: Make sure all the lentils are submerged so they cook evenly throughout.
2
Cook on low heat
- Cover the slow cooker with the lid and set to LOW.
- Cook for 6 hours.
- The lentils should be tender but still hold their shape, and the vegetables should be very soft and starting to break down.
- The liquid will have reduced slightly and thickened from the starch released by the lentils.
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Ready when: Lentils are tender but intact; vegetables are soft; sauce coats a spoon
Tip: Do not lift the lid frequently—this extends the cooking time. Resist peeking for at least the first 4 hours.
3
Remove herbs and adjust seasoning
- Remove and discard the bay leaf and thyme sprigs using a slotted spoon or tongs.
- Taste the lentils and vegetables.
- Add the Dijon mustard if using (it deepens the umami), and adjust the salt and pepper to your taste.
- The final dish should be savory and well-rounded, with the wine flavor subtle but present.
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Ready when: Herbs are removed; flavors are balanced
Tip: Add the mustard slowly—a little goes a long way. It adds complexity without making the dish taste mustardy.
4
Finish and serve
- Stir in the fresh parsley if using, which adds a bright, fresh contrast to the deep, earthy flavors.
- Spoon the lentils and vegetables into serving bowls, making sure to include plenty of the silky braising liquid.
- Serve warm as a vegetarian main course with crusty bread and a simple green salad, or alongside roasted chicken, fish, or lamb.
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Tip: If the braising liquid is too thin for your taste, use a slotted spoon to serve, or transfer the solid ingredients to a saucepan and simmer uncovered on medium-high heat for 10 minutes to reduce the liquid.

Good to know

Tips

Green lentils (lentilles du Puy) hold their shape much better than brown or red lentils during the long, slow cooking process. They won't turn to mush and will remain distinct in every spoonful.
Don't skip the initial wine—it adds acidity and complexity that balances the richness of the mushrooms and the earthiness of the lentils. If you're not a wine drinker, use dry vermouth instead.
This dish can be served immediately, but the flavors deepen significantly if you let it rest, covered, for 30 minutes after cooking is complete. The vegetables will soften even more, and the sauce will become silkier.
For a more elegant presentation, serve in shallow bowls with a drizzle of good olive oil, a sprinkle of fleur de sel, and fresh thyme leaves on top. A dollop of crème fraîche or sour cream adds richness and tang.

Make ahead

Assemble the slow cooker insert the night before: add all ingredients (except fresh parsley), cover, and refrigerate. In the morning, place the insert in the slow cooker base and cook on LOW for 6 hours. This is ideal for weeknight dinners with minimal morning effort.

Storage & reheating

Refrigerate leftovers in an airtight container for up to 4 days. The flavors actually deepen on the second day. Reheat gently on the stovetop over medium-low heat, stirring occasionally and adding a splash of broth or water if the mixture seems too thick. Do not refreeze after slow cooking due to the risk of bacterial growth, but you can freeze the uncooked assembled dish (in the slow cooker insert) for up to 3 months. Thaw in the refrigerator overnight before cooking.

Substitutions

cremini or baby bella mushrooms → Cremini mushrooms can be replaced with button mushrooms, portobello mushrooms (cut into smaller pieces), or oyster mushrooms. Keep the weight the same; cooking time remains unchanged.. Cremini and portobellos are meatier; buttons are milder. Choose based on your preference for depth of flavor.
dry white wine (such as Sauvignon Blanc) → If you prefer not to use wine, replace it with an equal amount of vegetable broth, or use 4 tablespoons (60 ml) of dry vermouth. The depth of flavor will shift slightly.. Wine adds acidity and subtle complexity. Omitting it makes the dish earthier and slightly sweeter.
fresh thyme sprigs → Fresh thyme can be swapped for 1 tablespoon (3 g) dried thyme, or replaced entirely with fresh rosemary sprigs (use 2–3 sprigs) or a combination of thyme and sage.. Dried thyme is more concentrated; use half the amount. Rosemary is more assertive and works well with mushrooms.
low-sodium vegetable broth → Vegetable broth can be replaced with chicken broth for a less vegetarian dish, or with mushroom broth for even deeper umami.. Chicken broth adds subtle poultry notes; mushroom broth amplifies the earthy, savory quality of the dish.