This vegetable casserole recipe is a budget-friendly favorite that’s easy to make and uses freezer staples for a buttery casserole with a deliciously crunchy topping.

Vegetarian casserole recipes are great vessels to sneak veggies into dinners or include more meatless meals into your weekly rotation. With a creamy texture and plenty of flavor, an easy vegetable casserole doesn’t have to be complicated to make.

For this recipe, I’ve used ingredients that you’re likely to already have in your freezer or pantry, like frozen mixed vegetables, tinned soup, and rice. It makes a hearty, flavorful meal that won’t break the bank. Plus, there are so many variations you can make on the recipe to cater to your own tastes.

For this vegetarian casserole, I’ve found that frozen veggies work great – there’s no need to thaw or pre-cook them as they cook to perfection while baking the casserole. Plus, they’re frozen at the point of peak freshness, so they have kept their nutritional benefits. You can use fresh vegetables if you prefer, but for a budget-friendly recipe, frozen is the way to go.

Ingredients Needed

• Frozen Mixed Vegetables: No need to defrost. In these packs, you’ll usually find green beans, broccoli, corn, peas, and carrots, though you can add your favorite veggies if you like. Leeks, celery, swede, parsnip, butternut squash, sweet potato, cauliflower, or mushrooms also work great in a vegetable casserole, though may need to be blanched before using.
• Cooked long-grain rice: I tend to use basmati rice for flavor, but you can also use wholegrain or any kind of rice you have to hand.
• Cream of Mushroom Soup: You can use homemade or store-bought – I prefer homemade just because you can control the amount of salt and fat that goes into it, but canned soup works just fine.
• Sour Cream: You can also use yogurt or cottage cheese if you don’t have sour cream to hand, but I recommend adding a little cider vinegar or lemon juice to achieve the sour flavor.
• Cheddar Cheese: Other hard cheeses (gouda, Emmental etc) and dairy-free cheese also work.
• Spices: I use a mix of Italian seasoning, salt, and pepper, though you can experiment with other flavors like fresh herbs.
• For The Topping: Crackers (I use Ritz crackers for the best flavor) and butter.
• To Garnish: Optional, sprinkle of parsley.

Recipe Variations

• For a healthier mixed vegetable casserole, use homemade cream of mushroom soup over a canned one (which often has a lot of salt and fat in it). You can also leave out the cheese and use low-fat crackers, or don’t use them at all.
• Add in frozen salad veggies, like frozen spinach, kale, brussels sprouts, or cabbage to add leafy greens – they’re packed with essential nutrients and, when frozen, they take up a lot less space than when they’re fresh.
• You can use fresh over frozen vegetables. Before using them in this recipe, blanch them in boiling water until tender, then drain and pat dry.
• If you want an alternative to Ritz crackers, you can use breadcrumbs – either already toasted or plain; this will keep the topping crunchy with much less fat and salt. Or, if you want to make this casserole gluten-free, try using crispy onions sprinkled over the top.
• Experiment with other seasonings and flavors to give the casserole a warmer flavor. Try Dijon, wholegrain or English mustard, garlic powder, bay leaf, tarragon, paprika (sweet or smoky), cayenne pepper, or chili powder.

How to Make Vegetable Casserole

Prepare the Casserole Elements

I make this casserole with already cooked rice (leftovers work great for this recipe!) and cream of mushroom soup. If you don’t have these elements, make sure to prepare them first. There’s no extra prep if you’re using canned soup and cooked rice.

Preheat the oven to 350ºF/175ºC.

Crush the Ritz crackers in a medium bowl. Or, for ease and keeping things clean, put the crackers in a large Ziplock bag and use a rolling pin or the bottom of a heavy glass to crush them into a chunky consistency. Don’t crush them with too much force as this can break the bag.

Melt the butter in a separate small pot on the stovetop or in short bursts in the microwave. Then, combine it with the crushed crackers until it just starts to come together.

Assemble the Casserole

In a 9.5×6.5 inch casserole or baking dish, add the frozen mixed veggies, then the cooked rice, cream of mushroom soup, sour cream, cheese, and seasonings. Mix all of the ingredients well and level off.

Add the crushed cracker topping, covering the veggies completely.

Bake the Casserole

Place the casserole dish in the oven and bake covered with foil for 30 minutes at 350ºF/175ºC. Then uncover and bake for an additional 10 minutes until the filling is bubbling and the Ritz crust is golden brown. If the casserole is browning unevenly, rotate the dish halfway through so the crust cooks all over.

Allow the casserole to cool for about 10 minutes, then garnish with the parsley (if desired) and enjoy!

This vegetable casserole is a great meatless option for Thanksgiving, weeknight dinners or incorporated into larger dinners as a side dish. I like to enjoy it with a simple green salad, some slices of crusty bread (great for mopping up the juices at the end – I like using fresh baguette or sourdough, but you can use whatever bread you have in your pantry), alongside a grilled chicken breast or a salmon filet.

Depending on your spice choices, this vegetable casserole can be adapted for any meal, and leftovers can be saved for lunches or stored.

Storing Instructions

Any leftovers will keep in the refrigerator for up to 4 days. Reheat the casserole in either the oven or the microwave and enjoy.

If you prefer, you can also freeze the casserole. Allow the casserole to cool before placing it in a freezer-safe airtight-container – it’ll keep in the freezer for up to 3 months.

Make Ahead Instructions

If you’re making vegetable casserole ahead of time, prepare the dish as per the instructions – but store the Ritz topping separately. Refrigerate the base of the casserole for 1-2 days before baking.

Allow the casserole to come to room temperature from the fridge before adding the toppings. Then, bake as directed.

More Casserole Recipes

• The Easiest Corn Casserole
• Quick and Easy Hamburger Casserole
• Million Dollar Chicken Casserole
• French’s Green Bean Casserole

If you try this vegetable casserole recipe, let me know how it goes in the comments below. I’d appreciate a recipe card rating and would love to see your recipe recreations – tag me on Instagram @Alphafoodie!