Preheat your oven to 400°F and lightly grease a 9x13 inch baking dish or similar size with cooking spray or oil. While the oven heats, dice the onion and bell pepper into 1/2-inch pieces, slice the black olives into thin rounds, and shred the romaine lettuce into thin ribbons. Slice the jalapeno into rings and halve the cherry tomatoes. This prep work ensures everything is ready when you need it, so the cooking process flows smoothly without interruption.

Heat 1.5 tablespoons of avocado oil in a large skillet over medium-high heat. Add the diced onion and bell pepper, sautéing for about 8 minutes until they soften and develop light golden edges, which builds flavor through caramelization. Transfer the softened vegetables to your prepared baking dish and spread them evenly across the bottom. In a bowl, whisk together the 4 room-temperature eggs, 1.25 teaspoons salt, and 0.75 teaspoon pepper until well combined, then pour this mixture evenly over the vegetables in the dish. The room-temperature eggs ensure even cooking throughout the casserole.

While the vegetable and egg mixture sits, heat 1.5 tablespoons of avocado oil in the same skillet over medium-high heat. Add the 2 pounds of ground turkey, breaking it apart with a spoon as it cooks, until it's completely browned and no pink remains (about 5-7 minutes). Sprinkle the 0.75 teaspoon garlic powder and 0.25 cup taco seasoning over the cooked turkey and stir well to coat evenly. Cook for 1-2 minutes to bloom the spices and release their flavors. I like to taste a small piece at this point to make sure the seasoning is balanced before moving forward.

Add the 14.5 ounces of well-drained diced tomatoes and 0.5 cup water to the seasoned turkey, stirring to combine thoroughly. Simmer this mixture over medium heat for 5-7 minutes, stirring occasionally, until it reduces slightly and the flavors meld together. The draining of the tomatoes is crucial—it prevents excess moisture from making the casserole watery and mushy. This concentrated taco meat will provide rich, flavorful layers in the final dish.

Carefully spread the hot seasoned turkey mixture from Step 4 in an even layer over the egg and vegetable base in the baking dish. Top uniformly with the 2.5 cups of shredded sharp cheddar cheese, then scatter the sliced black olives across the surface. Place the assembled casserole in the preheated 400°F oven and bake for 20 minutes until the cheese is melted and bubbly and the eggs are fully set.

Remove the casserole from the oven and let it rest for 3-5 minutes before serving. This resting period allows the eggs to fully set and makes portioning cleaner. Serve generous portions topped with the shredded romaine, fresh jalapeno slices, and cherry tomatoes for a fresh, crunchy contrast to the warm, cheesy casserole. I find that these fresh toppings added at the end really brighten the rich flavors and give each bite nice textural variety.