1. Preheat the oven to 350°F (175°C) and grease a 9×13-inch baking dish with butter.

2. Cube the sourdough bread into 1-inch pieces and toast in the oven for 10 minutes if the bread is fresh.

3. Melt butter in a skillet over medium heat and sauté onion and bell pepper until soft, about 5–7 minutes.

4. Add cooked sausage, ham, or bacon and optional greens to the skillet and cook until heated through, then remove from heat.

5. In a large bowl, whisk together eggs, milk, heavy cream, salt, pepper, and fresh herbs.

6. Layer half of the bread cubes in the prepared baking dish and sprinkle with half of the shredded cheese.

7. Spread the sautéed vegetables and meats over the bread layer, then pour the egg mixture evenly over the top.

8. Gently press the remaining bread cubes into the custard and top with the remaining cheese.

9. Cover the dish and refrigerate for at least 2 hours or overnight for best results if making ahead.

10. Remove from the refrigerator 20 minutes before baking, then bake uncovered for 45–55 minutes until golden and set.

11. Let the strata rest for 10–15 minutes before slicing and serving.