Can I use frozen vegetables?
Yes. Frozen mixed vegetables work great here. Thaw first and drain well, or you risk a watery casserole. I like to pat them dry with a clean towel, then proceed as written. Note: frozen broccoli and cauliflower can cook softer, so you can skip the blanch (or keep it to 1 minute) if they are already thawed.
How do I keep vegetable casserole from getting watery?
Two things: cook the vegetables briefly to help control moisture, and do not skip the drain if you blanch or steam. Let the vegetables steam-dry for a minute or two, too. Also, avoid adding extra milk beyond what is listed unless your mixture looks unusually tight.
What can I use instead of cream of mushroom soup?
Cream of chicken works, cream of celery is great, and for a vegetarian option look for a vegetarian “cream of” soup. You can also use a homemade quick sauce: make a roux with butter and flour, whisk in milk, then season and simmer until thick.
Can I make this gluten-free?
Yes. Use a gluten-free condensed soup (or homemade sauce thickened with cornstarch), and swap the crackers for gluten-free crackers or crushed gluten-free cornflakes.
Is this a side dish or a main?
Both. As written, it is a strong side for chicken, ham, or meatloaf. To turn it into a main, add 2 cups shredded rotisserie chicken or 1 can drained white beans, and serve it with a simple salad.
Can I make it ahead?
Yes. Assemble the casserole (without the cracker topping) up to 1 day ahead, cover, and refrigerate. Add the buttered cracker topping right before baking so it stays crisp. If baking straight from the fridge, add a few extra minutes to the bake time.
