Preheat oven to 350°F. Line two baking sheets with parchment paper. Place frozen naan on baking sheets. Top each piece of naan with 1/4 cup sauce, 1/3 cup cheese and 2 teaspoons onion jam.
Place baking sheet in oven on center rack (for best results, bake two pizzas at a time). Bake for 10 minutes. Turn broiler on high and and broil for 3-5 minutes, watching to ensure crust doesn't burn. Remove from oven and let pizza cool slightly before serving.