Ingredients
2 tablespoons olive oil
1 large yellow onion, cut into 1/4-inch rounds and separated into rings
3 sprigs thyme
1/2 teaspoon sugar
Salt and pepper
3 medium parsnips, peeled and cut into 1/8-inch rounds
All-purpose flour, for work surface
1 sheet frozen puff pastry, thawed
Preparation
Preheat oven to 400 degrees. In a 10-inch ovenproof skillet, heat oil over medium-high. Add onion, thyme, and sugar and cook until onion is softened, about 8 minutes; season with salt and pepper. Reduce heat to medium and spread onions evenly in pan. Add parsnips in an even layer, cover, and cook until almost tender, 8 minutes.
On a lightly floured work surface, trim pastry into a 10-inch round. Top parsnips with pastry. Bake until pastry is puffed and golden, 20 minutes. Let cool on a wire rack, 10 minutes, then invert.
