For the carrot purée

2 tablespoons olive oil

1/2 medium onion, chopped

1/2 pound carrots (about 3-4 medium carrots), peeled and thinly sliced

1/2 cup white wine

1/2 teaspoon kosher salt

1/4 cup mascarpone

1/8 teaspoon cayenne pepper

For the pizza

1/2 pound prepared pizza dough, room temperature

All-purpose flour (for surface)

Olive oil (for brushing)

8 ounces Fontina cheese, grated (about 2 cups)

1/2 medium red onion, root intact and thinly sliced lengthwise into wedges

1 cup (loosely packed) carrot fronds or baby arugula