How many servings does this recipe make?

This recipe makes 4 servings. You can adjust the portion size directly on this page.

What ingredients do I need for Easy, Cheesy Brunch Casserole?

You need 12 ingredients. The key ingredients include: 4 slices bread, 1 medium onion, chopped, 1 c. sliced mushrooms, 2 Tbsp. margarine, and more.

Is Easy, Cheesy Brunch Casserole suitable as breakfast?

Yes, Easy, Cheesy Brunch Casserole falls under the Breakfast category and is a great choice for this type of meal.

How do I store leftover Easy, Cheesy Brunch Casserole?

Store leftovers in an airtight container in the refrigerator for up to 3–4 days. Reheat gently before serving.

Easy, Cheesy Brunch Casserole Recipe

Name: Easy, Cheesy Brunch Casserole
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Yield: 4 servings
Ingredients: 4 slices bread; 1 medium onion, chopped; 1 c. sliced mushrooms; 2 Tbsp. margarine; 1 c. chopped ham or 1 lb. sausage; 1 c. (4 oz.) shredded Cheddar cheese; 1 c. (4 oz.) Swiss cheese; 1 Tbsp. flour; 1 1/2 c. milk; 4 large eggs, beaten; 1 Tbsp. prepared mustard; 1/2 tsp. garlic salt

Start your day right with this Easy, Cheesy Brunch Casserole recipe. Made with bread, onion, mushrooms and margarine. Easy step-by-step instructions inc…

This Easy, Cheesy Brunch Casserole relies on simple, everyday ingredients such as bread, medium onion, chopped, sliced mushrooms and margarine. It comes together quickly and makes 4 servings, at about 816 kcal each. The step-by-step instructions below are written to be easy to follow, even on a busy day.

It's an easy way to start the day, whether you're cooking a relaxed weekend breakfast or need something satisfying before a busy morning. Pair it with fresh fruit or your favorite hot drink to round out the meal.

Updated Jun 30, 2026

Serves 4 Breakfast

Tips for the best results

Read through all the steps once before you start and measure out your ingredients first — it makes everything go more smoothly.
Taste as you go and adjust the seasoning before serving.
Avoid overcrowding the pan — cook in batches if needed for the best texture.
Let the dish rest for a few minutes before serving so the flavors settle.
Store leftovers in an airtight container in the fridge and enjoy within a few days.

Variations & substitutions

A good 1:1 gluten-free flour blend works well if you need a gluten-free version.

No specific allergen information. Please check the ingredient list for possible allergens.

My Personal Notes

Saved locally in your browser — visible only to you.

Easy, Cheesy Brunch Casserole

Tips for the best results

Variations & substitutions

My Personal Notes

How did you like this recipe?

Frequently Asked Questions