1. Preheat the oven to 375°F (190°C). Fit the 9-inch deep-dish pie crust into a pie plate if needed and crimp the edges. Prick the bottom all over with a fork, line with parchment or foil, and fill with pie weights or dried beans. Blind-bake for 10–12 minutes, until the edges are lightly golden. Remove the weights and parchment and let the crust cool slightly while you prepare the filling.

2. While the crust bakes, place the bulk breakfast sausage in a skillet over medium heat. Cook, breaking it into small crumbles, for 6–8 minutes or until browned and no pink remains. Transfer the cooked sausage to a paper towel–lined plate to drain off excess fat.

3. Dice the roasted red bell peppers and pat them dry with paper towels to remove extra moisture. Slice the green onions or chives and chop the fresh parsley. Shred the sharp cheddar cheese if it is not already shredded and grate the Parmesan cheese.

4. In a large mixing bowl, whisk the eggs until the yolks and whites are fully combined and slightly frothy. Add the half-and-half, kosher salt, black pepper, garlic powder, and smoked paprika. Whisk again until the custard mixture is smooth and the seasonings are evenly distributed.

5. Sprinkle the cooked, drained sausage evenly over the bottom of the warm pie crust. Scatter the diced roasted red bell peppers over the sausage, then sprinkle the shredded cheddar cheese and most of the sliced green onions over the peppers, reserving a small pinch of onions for garnish after baking if desired.

6. Give the egg custard one last whisk, then slowly pour it over the layered sausage, peppers, and cheese in the crust. Gently tap the pie plate on the counter to help the custard settle and release any air bubbles.

7. Sprinkle the grated Parmesan cheese evenly over the top of the quiche. Place the pie plate on a baking sheet to catch any drips and transfer it to the oven. Bake at 375°F (190°C) for 35–40 minutes, or until the edges are puffed and golden and the center is mostly set but still has a slight jiggle when you gently shake the pan.

8. Remove the quiche from the oven and let it rest on a cooling rack for 10–15 minutes so the custard can finish setting. Sprinkle the top with the chopped fresh parsley and any reserved green onions. Slice into wedges and serve warm, or let it cool completely for firmer slices.