Instructions

• Preheat the oven to 375°F.
• Melt the tablespoon of butter in a small skillet over medium heat. Add the 3/4 cup diced onion and sauté, stirring occasionally, until the onion is tender and lightly browned, about 5 minutes. Transfer the cooked onion to a small bowl and set aside to cool slightly.
• Trim the asparagus by bending each spear to snap off the woody ends. Place the asparagus spears in a shallow microwave-safe bowl, add a little cold water, and microwave 1–3 minutes until crisp-tender. Drain and transfer the spears to ice water to stop the cooking. Drain and pat dry, then set aside.
• In a large bowl, whisk the 3 large eggs with the 3 tablespoons heavy cream and whole milk mixture until combined. Stir in the cooked onions, the 2 diced chicken sausages, and half of the 1 1/4 cups grated Dubliner cheddar cheese. Season with salt and pepper to taste and mix until evenly combined.
• Place the unbaked 10-inch tart shell on a baking sheet. Pour the egg and sausage mixture into the tart shell, spreading evenly.
• Arrange the asparagus spears on top of the filling and sprinkle with the remaining grated cheese.
• Cover the tart loosely with foil and bake at 375°F for 15 minutes. Remove the foil and continue baking 5–10 minutes more, until the center is set (a gentle jiggle only) and the top is lightly golden.
• Remove the quiche from the oven and let it cool for 10 minutes before slicing and serving.