Preheat your oven to 350°F (175°C). Fit thawed puff pastry into an 8 or 9-inch tart pan and refrigerate.

In a large skillet, melt 2 tablespoons of butter. Add chopped bacon and sauté until crispy, about 5-7 minutes.

Add onions, potatoes, and fresh dill, seasoning with salt and pepper. Sauté for another 3-5 minutes.

Remove from heat, spoon the potato mixture into the pastry crust, and drizzle with heavy cream.

Bake for 35-45 minutes until fork-tender and golden brown.

Let it rest for 10 minutes, garnish with chives or scallions, and serve warm.