“Sausage,” Spinach & Mushroom Casserole
Updated Dec 04, 2025, Published Oct 31, 2019
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Comforting & Gluten‑Free
Why This Casserole Works
This Vegetarian Sausage Spinach & Mushroom Casserole brings together savory sausage (or a meat‑free alternative), earthy mushrooms, fresh spinach, and creamy sauce for a hearty, satisfying dish. It offers robust flavor and comforting texture, making it ideal for breakfast, brunch, or dinner. Make the Vegetarian Sausage Spinach & Mushroom Casserole ahead of time, bake it, then enjoy the rich, layered taste — perfect for feeding a crowd or having leftovers for the week.
Because it uses gluten‑free lasagna noodles and carefully chosen ingredients, this casserole stays gluten‑free without compromising on taste or heartiness. The combination of protein, veggies, and creamy sauce also makes it a balanced and filling meal.
Table of Contents
What You’ll Need
For the sausage‑mushroom‑spinach base
- Olive oil (for sautéing)
- Vegan sausage (or regular sausage if not vegan) about 14 oz
- 1 medium onion, diced
- Sliced mushrooms — about 8 oz
- Vegetarian Sausage Spinach & Mushroom Casserole can include extra‑firm tofu (optional, for added texture or plant-based option) — about 7 oz
- Ground turmeric, nutritional yeast flakes, onion powder, garlic powder, salt & freshly ground black pepper (seasonings)
- Fresh spinach — roughly two handfuls
layering and structure
- Gluten‑free, oven‑ready lasagna noodles (package — 10 oz)
- Vegan shredded Parmesan-style cheese — ½ cup, plus extra for topping
- Vegan shredded mozzarella-style cheese (for topping)
creamy “hollandaise-style” sauce
- Vegan butter — 6 tablespoons
- Gluten-free all-purpose flour — 6 tablespoons
- Non-dairy cream or half-and-half (e.g. plant-based) — 1 cup
- Unsweetened almond milk (or another dairy‑free milk) — 2 cups
- Vegan mayonnaise — 2 tablespoons
- Dijon mustard — 4 teaspoons
- Nutritional yeast flakes — 4 tablespoons
- Lemon juice — 4 tablespoons
- Salt to taste
What Makes This Dish Great
This Vegetarian Sausage Spinach & Mushroom Casserole balances rich, savory flavors and a creamy texture. The sausage (or vegan sausage) brings hearty protein and warmth; mushrooms and spinach add earthy depth and vegetable goodness; and the creamy sauce wraps it all together, creating a cohesive, comforting dish. The gluten‑free lasagna noodles provide structure and make this a complete meal.
Because it layers ingredients — noodles, veggies, sausage, sauce, cheeses — the casserole develops complex flavor as it bakes, with creamy sauce melding into the noodles and vegetables softening to create a satisfying, homestyle texture. Its versatility makes it suitable for breakfast casseroles, brunch spreads, or dinner entrees.
Serving Ideas
- Serve warm straight from the oven, topped with extra vegan cheese or a sprinkle of fresh herbs for brightness.
- Pair with a crisp green salad or steamed vegetables for a balanced meal.
- Offer the Vegetarian Sausage Spinach & Mushroom Casserole at brunch or holiday breakfasts when you want a filling, savory dish without gluten.
- Make it a day ahead – bake, cool slightly, then reheat — flavors often deepen when made in advance.
Make It Your Own
You can easily adapt this casserole to match your dietary preferences or flavor cravings:
- Swap the sausage: Use regular sausage, turkey sausage, or a plant-based sausage depending on dietary needs.
- Vegetable substitutes: Replace mushrooms or spinach with other veggies like bell peppers, zucchini, or kale for variation.
- Boost the sauce: Add herbs (like thyme, basil, or oregano), a dash of hot sauce, or extra nutritional yeast for more flavor.
- Cheese options: Use a different dairy-free cheese alternative — or add a layer of shredded cheddar-style for a sharper taste.
- Make it richer or lighter: For a richer sauce, use full-fat non-dairy cream; for lighter, use more almond milk and less butter.
- Protein swap: Use crumbled tofu, cooked ground meat, or cooked ground turkey or chicken sausage.
- Personalize the texture: For a softer, more casserole‑like texture, use extra sauce; for a firmer bake, reduce sauce and increase noodle or veggie layers.
The Vegetarian Sausage Spinach & Mushroom Casserole offers a comforting, gluten‑free meal that blends protein, vegetables, and creamy sauce into a satisfying dish. Its layered structure and mix of textures make it versatile and crowd-pleasing — ideal for family meals, brunches, or make‑ahead dinners.
Because the ingredients and structure are flexible, you can easily adapt it to your dietary needs or taste preferences. Whether you go vegan, vegetarian, or keep meat in, this casserole delivers warmth, flavor, and comfort.
Use this as a base for your own variations, and enjoy a flexible Vegetarian Sausage Spinach & Mushroom Casserole recipe that feels like a home-cooked classic every time.
“Sausage,” Spinach & Mushroom Casserole
Ingredients
- 2 tablespoons olive oil
- 14 ounces vegan sausage, (I used Beyond Meat)
- 1 medium onion, , diced
- 8 ounces sliced mushrooms
- 7 ounces extra-firm tofu
- ¼ teaspoon ground turmeric
- 2 tablespoons nutritional yeast flakes
- ¼ teaspoon onion powder
- ¼ teaspoon garlic powder
- Kosher or fine sea salt, , to taste
- Freshly ground black pepper, , to taste
- 1 (10-ounce) package gluten-free, oven-ready lasagna noodles
- 2 handfuls spinach
- ½ cup vegan shredded Parmesan cheese, , plus more for topping
- Vegan shredded mozzarella cheese, , for topping
For the vegan hollandaise sauce:
- 6 tablespoons vegan butter
- 6 tablespoons gluten-free all-purpose flour
- 1 cup non-dairy cream/half-and-half , (I used Ripple Foods)
- 2 cup unsweetened almond milk
- 2 tablespoons vegan mayonnaise
- 4 teaspoons Dijon mustard
- 4 tablespoons nutritional yeast flakes
- 4 tablespoons lemon juice
- Kosher or fine sea salt, , to taste
Instructions
- Preheat the oven to 450°F. Grease a 2-quart baking dish with gluten-free nonstick cooking spray.
- In a large skillet, heat the olive oil over medium heat. Add sausage (casing removed) and cook per package directions. Push the sausage to one side of the skillet, then add onions and sauté for a few minutes. Add the mushrooms and sauté for an additional few minutes. Mix in with the sausage. Add tofu, turmeric, nutritional yeast, onion powder, garlic powder, salt, and pepper and sauté for about 5-7 minutes, then set aside.
- Make the hollandaise sauce. In a medium saucepan, melt the butter over medium heat, then whisk in the flour until the butter is absorbed by the flour. Turn heat to high, then add the creamer and almond milk and whisk to dissolve the flour, creating a roux. Add mayonnaise, mustard, nutritional yeast, lemon juice, and salt. Whisk continuously until it starts to come to a slow boil, then reduce the heat to low and let thicken for a few minutes, whisking occasionally.
- Set aside some hollandaise sauce for serving. Pour enough sauce into the prepared baking dish to cover the bottom. Layer the lasagna in this order: lasagna noodles, spinach, sausage mixture, hollandaise sauce, and Parmesan cheese. Repeat until you get to the top of the baking dish, ending with the hollandaise sauce. Top with additional Parmesan cheese and a handful of mozzarella.
- Cover with foil and bake 30-45 minutes, until the noodles are soft when a knife is inserted.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
