Cheesy Veggie Breakfast Bake

Onions, peppers, and broccoli provide texture and freshness but feel free to swap. Use kale or spinach if broccoli is out. Replace bell peppers with diced zucchini or mushrooms if preferred. Sharp cheddar is classic here; goat cheese or gruyere adds sophistication but melts differently—expect softer texture and shorter bake time if swapping. Half and half can be substituted with whole milk or cream based on richness desired, but adjust flour quantity accordingly if too thin or thick. Whole wheat flour absorbs moisture better than all-purpose here; all-purpose can be used but risks slightly more sogginess. Ground mustard powder adds flavor punch but may replace with ½ teaspoon dry mustard or a light sprinkle of turmeric to boost color without adding heat.

Spraying the casserole dish prevents the egg mixture from sticking while developing a nicely caramelized cheese crust on the edges. Spreading the vegetables evenly keeps consistent texture throughout each serving. Whisking eggs with mustard powder wakes up flavor molecules and thickens mixture gently, helping custard hold shape during baking. Adding flour stabilizes the bake, reducing watery leaks common in egg-heavy dishes. Pouring mixture slowly over vegetables avoids floating chunks or separation. Baking at moderate temperature allows the custard to set firmly without burning or drying out. Reliable doneness signals: edges firm and pulling slightly from the pan, center jiggles faintly when nudged, top cheese bubbling and browning. Adding cheese after initial bake ensures crisp golden topping, not burnt through. Resting the casserole for several minutes post-oven lets the proteins settle and prevents crumbling during slicing. Use a sharp serrated knife for clean cuts. If edges cook faster than center next time, tent dish with foil for part of bake to avoid over-browning. Leftovers reheat well wrapped in foil, retain texture if gently warmed. A blowtorch on cheese finish elevates presentation but isn’t required.