Rotini, mushrooms, onion and green pepper bake in a creamy tomato sauce with sour cream and grated cheese. Half the grated cheese goes into the pasta mixture and half forms the topping, keeping the ingredient list and method consistent.
Recipe Details
- Pan: 9×12 inches
- Oven: 350°F (175°C)
- Bake: 20 minutes covered, then about 10–15 minutes uncovered
- Rest: 5 minutes
Ingredients
- 454 g rotini pasta, or the same weight of spaghetti or elbow pasta
- 1/2 teaspoon kosher salt, plus salt for pasta water as needed
- 2 tablespoons unsalted butter, for the baking dish
- 2 tablespoons olive oil
- 1 tablespoon minced garlic
- 1 medium green bell pepper, diced
- 1 medium onion, chopped
- 227 g mushrooms, sliced
- 1/2 teaspoon black pepper
- 3 cups grated mozzarella, Italian-blend or cheddar cheese, divided
- 60 ml sour cream
- 794 g red pasta sauce
How to Make Creamy Vegetable Pasta Bake
Prepare the oven and pasta
Heat the oven to 350°F (175°C). Grease a 9×12-inch baking dish with the butter. Cook the pasta in salted water until al dente according to its package, then drain.
Cook the vegetables
Heat the olive oil in a skillet. Sauté the onion, pepper and mushrooms until softened and excess mushroom liquid has reduced. Stir in the garlic near the end so it does not burn.
Make the creamy sauce
Add the red pasta sauce, 1/2 teaspoon salt and black pepper and warm through. Remove from the heat, then gently stir in the sour cream and 1 1/2 cups grated cheese.
Assemble and bake covered
Combine the cooked pasta with the sauce and vegetables. Spread in the buttered dish, cover with foil and bake for 20 minutes.
Add the topping
Remove the foil, sprinkle with the remaining 1 1/2 cups cheese and bake for about 10–15 minutes, until melted and hot throughout. Check the center for 165°F (74°C), especially if assembled from chilled components.
Rest and serve
Let the bake stand for 5 minutes before serving.
Tips and Common Mistakes
- Cook the pasta only to al dente before baking.
- Cook off mushroom moisture so the sauce does not become watery.
- Add sour cream off the direct heat and avoid vigorous boiling.
- Divide the 3 cups grated cheese before starting.
- This measured version uses sour cream and grated cheese throughout the sauce and topping.
Storage and Make-Ahead Tips
Refrigerate leftovers within 2 hours in shallow covered containers and use within 3–4 days. Reheat to 165°F (74°C). A casserole assembled ahead should be kept refrigerated and baked within 24 hours, with extra heating time as needed.
Frequently Asked Questions
Can I use spaghetti instead of rotini?
Yes. Use the same 454 g weight and cook according to the package until al dente.
How is the cheese divided?
Mix 1 1/2 cups into the sauce and use the remaining 1 1/2 cups for the topping.
Why did the sour cream separate?
Strong heat can make it separate. Remove the sauce from direct heat before stirring it in and avoid a hard boil.