Best Vegetarian Broccoli Casserole

This is the classic broccoli rice casserole rebuilt for vegetarians. Brown rice replaces the typical white, two cream soups (mushroom and celery) provide the rich saucy backbone, and a small handful of diced American cheese melts through the dish for that classic potluck-casserole gooeyness. Broccoli florets stay tender-bright and meaty enough to hold their own as the main protein.

The two-soup combination is the technique that gives this version its depth. Cream of mushroom alone makes a one-note casserole; adding cream of celery contributes a savory herbal undertone that complements the actual celery and onion sweated into the dish. The combination produces a sauce that tastes more layered than a single canned soup ever could.

Brown rice (or a brown-and-wild blend) is the right call for a vegetarian version. Without meat to provide bulk and chew, you need the rice to do more work. White rice goes mushy in long bakes; brown rice holds its texture and contributes nutty flavor that pairs naturally with the broccoli and cream soups.

American cheese is the unsung hero. Real cheddar can break and turn greasy in a long baked casserole; American cheese contains emulsifiers that keep it smooth and creamy throughout the bake. If you want better flavor, mix half American with half sharp cheddar.

Olive oil instead of butter for sweating the vegetables nudges the dish in a slightly Mediterranean direction without being weird about it. Vegan margarine works as the substitute the recipe calls out, making the casserole fully plant-based when paired with vegan cheese and dairy-free cream soups.

Pro Tips

• Cook the rice slightly underdone. It will continue to cook in the oven, and pre-cooked-to-tender rice turns mushy in the long bake.
• Steam fresh broccoli only until just tender-bright. Overcooked broccoli loses color and texture during the casserole bake.
• Sauté the onion and celery until truly soft, not just translucent. They won’t soften further in the casserole.
• Cover with foil for the first half of the bake if the top browns too fast.

Variations

• Swap chickpeas, lentils, or cubed tofu in for an extra protein boost.
• Top with crushed croutons or breadcrumbs tossed in olive oil for the last fifteen minutes for a crunchy crust.
• Substitute cauliflower for half the broccoli for a more interesting vegetable mix.