Easy Frozen Vegetable Casserole
This Easy Frozen Vegetable Casserole is made with mixed frozen vegetables, pasta, and a creamy homemade white sauce finished with plenty of melted cheese. It’s an affordable family dinner that’s comforting, filling, and perfect for busy weeknights.
A Freezer Staple Turned Dinner.
I always seem to forget about this dinner until I make it again. I’ve been making versions of this vegetable casserole for years whenever I need something large and hearty enough to feed the family without a trip to the supermarket. It uses ingredients I almost always have sitting in the freezer or pantry! Sam x
No Last-Minute Grocery Run – made with ingredients many of us already have on hand
No Fuss – simple ingredients transformed into a creamy family dinner
Great For Busy Nights – minimal prep and plenty of hands-off baking time
Frozen vegetable casserole video
Why this recipe works
This frozen vegetable casserole turns simple freezer and pantry staples into a creamy, satisfying family dinner:
Frozen Mixed Vegetables
Add colour, texture, and convenience without any washing, peeling, or chopping.
Pasta
Makes the casserole hearty and filling while soaking up the creamy cheese sauce.
Homemade White Sauce
Made from butter, flour, milk, and seasoning for a rich, comforting base.
Cheddar Cheese
Melts into the sauce and creates a golden, bubbly topping once baked.
Ingredients you’ll need
Frozen Mixed Vegetables
I use a mixture of carrots, broccoli, cauliflower, and green beans, but any frozen vegetable blend works well.
Frozen Peas
Add sweetness, colour, and extra vegetables to the casserole.
Fusilli Pasta
Also known as spiral pasta. Penne, shells, macaroni, or other short pasta shapes can be substituted.
Butter
Forms the base of the white sauce and adds richness.
All-Purpose Flour
Thickens the sauce and creates a smooth, creamy consistency.
Whole Milk
Creates a rich sauce that coats the vegetables and pasta beautifully.
Ground Nutmeg
Adds a subtle warmth that complements the creamy sauce.
Cheddar Cheese
Provides flavour throughout the casserole and creates the golden cheesy topping.
How to make frozen vegetable casserole
Step 1: Set your oven to 200ºC (400ºF). Grease a 9×13 inch rectangle baking dish with butter or oil cooking spray. Set aside. Take out the frozen vegetables and set them aside in a bowl at room temperature. No need to completely thaw.
Step 2: Cook 1 1/2 cups pasta according to the packet instructions until al dente, which took me about 9 minutes. Once cooked, drain the pasta and set it aside.
Step 3: In a large deep skillet or pot, melt butter over low heat.
Step 4: Once melted, whisk in the flour. Increase the heat to medium, and cook the mixture for 1 minute as it bubbles/simmers, whisking continuously.
Step 5: Gradually pour in the milk, about 1/2 cup at a time, whisking well after each addition. Continue cooking and whisking over medium – high heat until the sauce thickens, taking care to not let it boil.
Step 6: Once thickened, reduce the heat to low, add ground nutmeg, and season with salt and pepper to taste. Whisk well.
Step 7: Add the 2 cups of cheese and whisk until melted through.
Step 8: Add the partially thawed vegetables and the cooked pasta to the white sauce. Mix until everything is well coated.
Step 9: Transfer the mixture into the greased baking dish. Sprinkle the remaining 1 cup of cheese evenly over the top. Bake for 30-35 minutes, or until the top is golden and the casserole is bubbling. Remove from the oven and let it side for 5 minutes before serving. Enjoy!
Can I use fresh vegetables instead of frozen?
Absolutely! Fresh vegetables can be used in this vegetable casserole. Just ensure they are cut into small, uniform pieces for even cooking. If you’re using bigger root vegetables, you may like to steam or boil them beforehand.
How to store
Store: Cool the casserole completely and store it in an airtight container in the fridge for up to 3-4 days.
Freeze: You can also freeze the casserole, either whole or in portions. Wrap it well in plastic wrap and foil, label it with the date and freeze for up to 2 months.
Reheat: Thaw overnight in the fridge if frozen, then reheat in the oven at 180ºC (350ºF) until warmed through.
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Easy Frozen Vegetable Casserole
Ingredients
Equipment
Method
- Preheat Oven & Prepare Casserole Dish: Set your oven to 400ºF (200ºC). Grease a 9×13 inch rectangle casserole dish with butter or oil cooking spray. Set aside.
- Thaw Veggies Partially: Take out the frozen vegetables and set them aside at room temperature. No need to completely thaw, just allow them to become slightly less frozen.
- Cook Pasta: Bring a pot of water (half-filled) to a boil, add 1/2 tablespoon of salt, and then add the pasta. Cook according to the packet instructions until al dente, which took me about 9 minutes. Once cooked, drain the pasta and set it aside.
- Melt Butter:Â In a large deep skillet or pot, melt butter over low heat.
- Make Roux:Â Once melted, whisk in the flour. Increase the heat to medium, and cook the mixture for 1 minute as it bubbles/simmers, whisking continuously.
- Add Milk:Â Gradually pour in the milk, about 1/2 cup at a time, whisking well after each addition. Continue cooking and whisking over medium – high heat until the sauce thickens, taking care to not let it boil.
- Season:Â Once thickened, reduce the heat to low, add ground nutmeg and season with salt and pepper to taste. Whisk well.
- Add Cheese: Add 2 cups of cheese and whisk until melted through.
- Combine, Veggies, Pasta & Cheese: Add the partially thawed vegetables and the cooked pasta to the white sauce. Mix until everything is well coated.
- Assemble Casserole: Transfer the mixture into the greased casserole dish. Sprinkle the remaining 1 cup of cheese evenly over the top.
- Bake: Bake for 35-40 minutes, or until the top is golden and the casserole is bubbling.
- Serve: Remove from the oven and let it side for 5 minutes before serving. Enjoy!
Nutrition
Video
Notes
- Store: Cool the casserole completely and store it in an airtight container in the fridge for up to 3-4 days.
- Freeze: You can also freeze the casserole, either whole or in portions. Wrap it well in plastic wrap and foil, label it with the date and freeze for up to 2 months.
- Reheat: Thaw overnight in the fridge if frozen, then reheat in the oven at 180ºC (350ºF) until warmed through.