1-Prepare the bread: Cube 12 slices of thick-sliced bread (about 14 cups total). To prevent sogginess, slightly dry the bread by leaving it out overnight or warming it in a 300°F oven for 10 minutes just enough to remove moisture without browning.

2-Grease your baking dish: Lightly grease a 9×13-inch baking dish with butter or nonstick spray.

3-Layer the ingredients: In the greased dish, add half the bread cubes, followed by half the meat (bacon or ham), green onions, red bell pepper, and cheese. Repeat the layers with the remaining ingredients.

4-Make the custard: In a large bowl, whisk together 6 large eggs, 3 cups milk, ½ teaspoon dry mustard powder, ½ teaspoon salt, and ½ teaspoon black pepper until fully blended.

5-Soak the casserole: Pour the egg mixture evenly over the layered ingredients, ensuring all bread cubes are moistened. Gently press down to help the liquid absorb.

6-Chill overnight: Cover the dish tightly with foil or plastic wrap and refrigerate for at least 3 hours or ideally overnight.

7-Bake to perfection: Before baking, let the casserole sit at room temperature for 20 30 minutes. Preheat your oven to 350°F. Bake covered with foil for 45 55 minutes, or until the center is set. For a golden, crispy top, broil for about 3 minutes at the end.