Mushroom Spinach Quinoa Bake

Name: Mushroom Spinach Quinoa Bake
Prep time: 25 min
Cook time: 30 min
Total time: 55 min
Yield: 6 servings
Cuisine: American
Ingredients: 1½ cup (270 g) quinoa, rinsed, rinsed in a fine-mesh sieve; 3 cup (720 ml) vegetable or chicken broth; 1 lb (450 g) fresh mushrooms (cremini, baby bella, or button), cleaned and sliced ¼ inch thick; 6 oz (170 g) fresh spinach, roughly chopped; 1 can (10.5 oz) (298 g) cream of mushroom soup (canned); ½ cup (120 ml) whole milk or half-and-half; 1½ cup (150 g) sharp cheddar cheese, shredded, packed lightly; ¾ cup (85 g) panko breadcrumbs; 4 tablespoon (60 g) unsalted butter, divided, cold, divided (2 tablespoon for sautéing, 2 tablespoon for topping); ½ whole (110 g) yellow onion, medium, finely diced; 3 whole (15 g) garlic cloves, minced; 1 tablespoon (3 g) fresh thyme sprigs (or 1 teaspoon dried), leaves stripped from stems (if using fresh); to taste kosher salt; to taste freshly ground black pepper

From the MyKitchenBank Kitchen

A hearty, vegetarian casserole combining nutty quinoa with sautéed mushrooms and fresh spinach, bound together with creamy mushroom soup and melted cheddar cheese, then topped with crispy buttered breadcrumbs. Ready in under an hour, this dish is satisfying as a main course or generous side.

Prep: 25 min
Cook: 30 min
Wait: 15 min
Total: 1 hr 10 min
Makes: 1 9×13-inch (23×33 cm) bake, 6 servings

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Ingredients

6 servings

1½ cup (270 g) quinoa, rinsed, rinsed in a fine-mesh sieve
3 cup (720 ml) vegetable or chicken broth
1 lb (450 g) fresh mushrooms (cremini, baby bella, or button), cleaned and sliced ¼ inch thick
6 oz (170 g) fresh spinach, roughly chopped
1 can (10.5 oz) (298 g) cream of mushroom soup (canned)
½ cup (120 ml) whole milk or half-and-half
1½ cup (150 g) sharp cheddar cheese, shredded, packed lightly
¾ cup (85 g) panko breadcrumbs
4 tablespoon (60 g) unsalted butter, divided, cold, divided (2 tablespoon for sautéing, 2 tablespoon for topping)
½ whole (110 g) yellow onion, medium, finely diced
3 whole (15 g) garlic cloves, minced
1 tablespoon (3 g) fresh thyme sprigs (or 1 teaspoon dried), leaves stripped from stems (if using fresh)
to taste kosher salt
to taste freshly ground black pepper

Equipment (7)

9×13-inch (23×33 cm) baking dish
Medium saucepan with lid
Large skillet
Wooden spoon or spatula
Measuring cups and spoons
Knife and cutting board
Fine-mesh sieve

Steps

Before you start

Preheat your oven to 375°F (190°C)
Rinse the quinoa in a fine-mesh sieve under cold water
Have all vegetables prepped and measured before you begin cooking

1
Cook the Quinoa
- In a medium saucepan, bring the 3 cups of broth to a boil over high heat.
- Add the rinsed quinoa, stir once, and return to a boil.
- Lower heat to medium-low, cover, and simmer for 15 minutes until the quinoa is tender and the liquid is absorbed.
- Remove from heat, let stand covered for 5 minutes, then fluff with a fork.
- Set aside.
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Ready when: Grains are translucent and tender; all liquid is absorbed
Tip: Rinsing quinoa removes bitterness. Do not skip this step.
2
Preheat the OvenOven 375°F / 190°C
- If you haven't already, preheat your oven to 375°F (190°C).
3
Sauté Mushrooms and Onion
- While the quinoa is cooking, melt 2 tablespoons butter in a large skillet over medium-high heat.
- Add the diced onion and cook for 3 minutes, stirring occasionally, until softened and lightly golden.
- Add the sliced mushrooms and minced garlic, and cook for 6–8 minutes, stirring occasionally, until the mushrooms release their liquid and begin to brown.
- The pan should smell rich and earthy.
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Ready when: Mushrooms are golden brown and have released and reabsorbed their moisture; onions are soft
Tip: Don't crowd the pan. Let mushrooms brown before stirring to develop flavor. If needed, work in two batches.
4
Add Spinach and Thyme
- Add the chopped spinach and fresh thyme (or 1 teaspoon dried thyme) to the skillet.
- Stir constantly for 1–2 minutes until the spinach is wilted and any excess liquid has evaporated.
- Season with salt and pepper to taste.
- Remove from heat.
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Ready when: Spinach is completely wilted and bright green
Tip: Wilting spinach down removes excess moisture so the bake isn't watery.
5
Combine Filling Ingredients
- In a large mixing bowl, combine the cooked quinoa, mushroom-spinach mixture, cream of mushroom soup, and milk.
- Stir thoroughly until everything is evenly distributed and the mixture is smooth.
- Fold in 1 cup of the shredded cheddar cheese.
- Taste and adjust seasoning with salt and pepper.
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Ready when: Mixture is evenly combined and creamy
Tip: Don't overmix; a few streaks of cheese are fine. Overmixing can make the quinoa mushy.
6
Transfer to Baking Dish
- Pour the quinoa mixture into a 9×13-inch (23×33 cm) baking dish and spread it into an even layer, pressing gently with a spatula.
- The mixture should be packed loosely but evenly filled.
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Ready when: Mixture fills the dish evenly
Tip: Use a lightly oiled dish so the bake doesn't stick to the bottom.
7
Make Breadcrumb Topping
- In a small bowl, combine the panko breadcrumbs with the remaining ½ cup cheddar cheese and the remaining 2 tablespoons melted butter.
- Mix with a fork until the breadcrumbs are evenly coated and moistened.
- Spread the mixture evenly over the top of the quinoa bake.
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Ready when: Topping is evenly distributed and moist
Tip: Buttering the breadcrumbs ensures they toast golden instead of staying pale.
8
Bake Until GoldenOven 375°F / 190°C
- Bake in the preheated 375°F (190°C) oven for 25–30 minutes, until the top is golden brown and the filling is bubbling around the edges.
- The edges may puff slightly and bubble up; that's a good sign the bake has heated through.
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Ready when: Breadcrumb topping is deep golden brown; filling bubbles around the edges
Tip: If the topping browns too quickly, tent loosely with foil for the last 10 minutes.
9
Cool and Serve
- Remove the bake from the oven and let it rest on the counter for 5 minutes before serving.
- This allows the filling to set slightly so it doesn't fall apart when you scoop it out.
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Ready when: Bake has cooled slightly and smells deeply savory
Tip: Resting prevents the bake from collapsing when you cut into it.

Good to know

Tips

Toast the breadcrumb topping separately in a small skillet with melted butter over medium heat for 2–3 minutes before sprinkling it on if you prefer extra crispness.
For a lighter version, substitute the cream of mushroom soup with 1 cup of sautéed mushroom sauce made from fresh mushrooms, garlic, thyme, and vegetable broth thickened with a splash of cornstarch.
Pair with a simple green salad dressed with lemon vinaigrette to balance the richness of the bake.
This dish works well as a vegetarian main course or as a hearty side dish alongside roasted chicken or turkey.

Make ahead

You can assemble the bake up to 8 hours ahead: prepare the filling as directed, transfer to the baking dish, cover tightly with plastic wrap, and refrigerate. When ready to bake, top with the breadcrumb mixture and add 5–10 minutes to the baking time (the filling will be cold). Alternatively, prepare all components separately (cooked quinoa, sautéed vegetables, and sauce) and combine right before baking.

Storage & reheating

Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat individual portions in the microwave (2–3 minutes) or reheat the whole bake covered in a 325°F (163°C) oven for 15–20 minutes until warmed through. This dish does not freeze well due to the breadcrumb topping becoming soggy upon thawing.

Substitutions

cream of mushroom soup (canned) → Cream of chicken soup or cream of celery soup. Cream of chicken provides a milder flavor; cream of celery adds herbaceous notes. Use the same quantity.
sharp cheddar cheese, shredded → Gruyère, fontina, or Monterey Jack cheese. Gruyère adds nuttiness; fontina is creamy and mild; Monterey Jack is buttery. Shred fresh cheese for best melting.
fresh spinach → Frozen spinach (thawed and drained) or kale (chopped fine). Use 5 oz frozen spinach, squeeze out all moisture. Kale adds a slight bitterness and tougher texture; use slightly less (4–5 oz).
panko breadcrumbs → Regular breadcrumbs, crushed crackers, or crushed croutons. Regular breadcrumbs will brown more quickly and less crisply. Crackers or croutons add extra flavor and crunch.