Make Ahead Sausage and Vegetable Egg Casserole

This Easy Sausage and Veggie Egg Casserole makes the perfect high-protein, savory breakfast — loaded with colorful vegetables, leafy greens, and flavorful turkey sausage. It’s simple to assemble, easy to customize, and a crowd-pleaser for mornings when you need something hearty and satisfying.

This casserole is ideal for busy weekdays, weekend brunch, holidays, or meal prep. The combination of protein from eggs and sausage plus a generous portion of vegetables makes it filling without being heavy. It reheats well and freezes beautifully, so you can prepare it ahead of time and enjoy quick breakfasts all week. Below you’ll find clear ingredient details, step-by-step instructions, variations, and storage tips to make this recipe your go-to savory breakfast.

Why You’ll Love This

• Hearty, healthy, and flavorful — perfect for a satisfying breakfast or brunch.
• High in protein (about 16 grams per serving), making it a great low-carb breakfast option.
• Extremely versatile: swap vegetables, cheeses, or meats to suit preferences or dietary needs.
• Great for meal prep — can be made as a full casserole or baked as individual egg muffins.

Ingredients You’ll Need

• 12 large eggs — use fresh eggs to fill a 9×13-inch pan.
• 1 lb ground sausage — lean ground turkey or chicken sausage works well. You can substitute pork sausage, crumbled bacon, or a breakfast sausage of your choice.
• 1 Tbsp olive oil — for sautéing the vegetables.
• 1/2 cup onion, chopped — white, yellow, or sweet onion; green onions for garnish are optional.
• 1 red bell pepper and 1 green bell pepper, diced — any color pepper works; use red and green for festive color.
• 3 cups baby spinach, roughly chopped — spinach cooks down considerably, so pack it in.
• 2 green onions, chopped — optional, for extra flavor and garnish.
• 1/3 cup half-and-half — or milk of choice; milk, skim milk, almond milk, Greek yogurt, or sour cream can be used to adjust creaminess.
• 1 1/2 cups shredded sharp cheddar — or any cheese you prefer (Colby Jack, Monterey Jack, Swiss, pepper jack, goat cheese).
• Seasonings: 1/2 tsp salt, 1/4 tsp black pepper, 1 tsp dried mustard (optional). Add herbs or paprika to taste.

How to Make Sausage Egg Casserole

1. Preheat the oven to 350°F (175°C).
2. Brown the sausage. In a large skillet over medium-high heat, cook the ground sausage until fully browned and crumbled, about 5–7 minutes. Transfer the cooked sausage to a plate and drain excess fat if necessary.
3. Sauté the vegetables. Add a drizzle of olive oil to the skillet. Sauté the chopped onion and diced bell peppers over medium heat until the onions are translucent and peppers are softened, about 6 minutes. Stir in the chopped spinach and cook until just wilted.
4. Layer in the pan. Coat a 9×13-inch casserole dish with nonstick spray or a light brush of oil. Spread the cooked sausage and sautéed vegetables evenly in the dish and sprinkle with chopped green onions if using.
5. Whisk the eggs and dairy. In a large bowl, whisk together the 12 eggs, 1/3 cup half-and-half (or milk), salt, pepper, and dried mustard. Stir in 1 1/2 cups shredded cheese so it’s evenly distributed.
6. Combine and bake. Pour the egg and cheese mixture over the sausage and vegetables, gently mixing so the ingredients are evenly distributed. Bake in the preheated oven for 35–40 minutes, until the top is set and the edges are slightly golden. Allow the casserole to rest for 5 minutes before slicing and serving.

Variations and Substitutions

This casserole is extremely adaptable — feel free to make it your own.

• More veggies: Add mushrooms, shredded carrots, broccoli florets, zucchini, asparagus, kale, or roasted vegetables.
• More filling: For a heartier, higher-carb casserole, fold in whole grain bread cubes, crescent roll pieces, or shredded hash browns.
• Make it spicy: Add diced jalapeños, a pinch of cayenne, or red pepper flakes. Top individual servings with hot sauce.
• Cheese and meat swaps: Try smoked gouda, pepper jack, or feta; swap turkey sausage for pork, chicken, or plant-based crumbles.
• Egg muffins: To make portable breakfast portions, divide the cooked sausage and veggies among greased muffin tins, pour the egg mixture into each tin about two-thirds full, and bake at 375°F for 20–25 minutes until set. Cool, then refrigerate or freeze for quick breakfasts.

Make-Ahead and Freezing

You can assemble this casserole the night before to save morning time. Cover it tightly with plastic wrap or foil and refrigerate overnight. Remove from the fridge about 30 minutes before baking so it reaches near room temperature and cooks evenly. For freezing, bake first and cool completely, then wrap the entire pan with plastic wrap and foil or cut into individual portions and wrap each piece. Freeze for up to two months.

Prepping and Storage

To store: Keep leftovers in an airtight container in the refrigerator for 4–5 days. Reheat individual servings in the microwave or warm the whole dish in a 350°F oven until heated through.

To thaw and reheat from frozen: Thaw overnight in the refrigerator, then warm at 350°F for about 25 minutes, or heat individual portions in the microwave until hot.

Serving Suggestions

Serve slices of this casserole with breakfast potatoes, fresh fruit, a side salad, or warm toast. It pairs well with a dollop of Greek yogurt or a drizzle of hot sauce for extra flavor. This dish is also a welcome addition to holiday brunch spreads and family gatherings because it feeds a crowd and can be prepared ahead.

Recipe Details

Nutrition (approximate per serving)

Serving: 1/12 of recipe — Calories: ~230 kcal; Carbohydrates: ~3.9 g; Protein: ~16.3 g; Fat: ~16.8 g; Saturated Fat: ~6.7 g; Cholesterol: ~262 mg; Sodium: ~519 mg; Fiber: ~0.8 g; Sugar: ~1.3 g. Nutrition values are approximate and will vary with ingredient choices.

Notes

• Leftovers keep well in the refrigerator for 4–5 days in an airtight container.
• Freeze baked casserole (whole or in individual slices) up to two months; wrap tightly to prevent freezer burn.

Hope you enjoy this Sausage and Veggie Egg Casserole! If you make it, please leave a star rating or comment on the recipe page and tag your photos on Instagram with #eatyourselfskinny — I love seeing your recreations!

More Breakfast Casserole Ideas

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• Mixed Berry French Toast Casserole
• Overnight Blueberry French Toast Casserole
• Baked Egg and Roasted Veggie Casserole
• Raspberry Almond Baked Oatmeal