Preheat your oven to 375°F. While it heats, dice the onion into 1/4-inch pieces, dice the red bell pepper into 1/2-inch pieces, drain and rinse the black beans, and shred both the cheddar and mozzarella cheeses. Measure out the green chili peppers, spices, and thaw the hash browns if frozen. Having everything prepped before you start cooking ensures the casserole comes together smoothly without scrambling for ingredients.

Heat a large skillet over medium-high heat and cook the pork sausage, breaking it into small pieces as it cooks, until it's fully browned (about 8-10 minutes). Add the diced onions and cook for another 2-3 minutes until they're softened and fragrant. I like using Jimmy Dean sausage because it has great flavor and renders nicely without too much grease. Drain excess fat if needed, leaving just enough to coat the pan.

Add the diced red bell pepper, drained black beans, green chili peppers, chili powder, and 1 teaspoon of ground cumin to the cooked sausage. Stir everything together and let it cook for 2-3 minutes so the spices bloom and the flavors meld. I prefer freshly ground cumin when I can get it—the aroma is noticeably more vibrant than pre-ground. This step creates the savory foundation of your casserole.

Remove the skillet from heat and stir in the shredded cheddar cheese, mozzarella cheese, and thawed hash browns until evenly distributed throughout the sausage mixture. The residual heat will help the cheese blend in smoothly without clumping. This creates your casserole's hearty base that will hold the egg custard.

In a bowl, whisk together the room temperature eggs, heavy cream, remaining chili powder, and remaining ground cumin until well combined. Room temperature eggs incorporate more smoothly into the cream and create a more uniform custard. This mixture will be the binding agent that turns your casserole into a complete dish when it bakes.

Butter a 9x13-inch baking dish generously with the melted butter. Spread half of the sausage mixture from Step 4 into the prepared dish, then pour half of the egg custard over it. Add the remaining sausage mixture as the second layer, then pour the remaining egg custard evenly over the top. Bake uncovered at 375°F for 40-50 minutes until the eggs are set but still have a slight jiggle in the center—this ensures a creamy interior rather than a rubbery casserole. Let it cool for 10-15 minutes before serving; this allows the eggs to fully set and makes it easier to cut clean portions.