In a large skillet, melt 2 tablespoons of unsalted butter over medium heat. Add sliced leeks and minced garlic, sautéing until soft and translucent, about 3-4 minutes. Toss in chopped asparagus, stirring briefly for 2 minutes until tender-crisp. Transfer mixture to a bowl to cool slightly while preparing filling.

In a mixing bowl, crack 4 large eggs and whisk until lightly frothy and pale yellow, about 1 minute. Gradually add 1 cup of full-fat cream, followed by salt, pepper, and freshly chopped dill. Stir well until all ingredients are combined.

Prepare your quiche crust according to the package instructions. Layer the sautéed leeks and asparagus mixture in the crust, followed by 200 grams of smoked salmon, tearing it into bite-sized pieces. Pour the smooth egg and cream mixture over the top, ensuring even coverage.

Preheat your oven to 350°F (175°C). Once assembled, place the quiche on the middle rack and bake for about 30-40 minutes until the custard is set and a knife inserted comes out clean. Look for a golden-brown crust forming around the edges.

After baking, remove the quiche from the oven and let cool for about 10-15 minutes on a wire rack. Slice into wedges and serve warm or at room temperature.