Preheat oven to 375°F. Line a baking sheet with parchment paper. Place 3 tablespoons of cheese on the paper and, with a spoon, spread into a 6-inch circle. Repeat with the remaining cheese to make 4 circles. Bake until lightly browned around the edges, 6 minutes.
Meanwhile, place 4 custard cups or small shallow bowls upside down on a countertop. Working one at a time, carefully remove the hot cheese circles from the baking sheet and place over the cups. Let stand to form cups and cool completely.
Place the tomatoes in a roasting pan and drizzle with the oil. Roast until the tomatoes split, 10 minutes. Add the basil, tossing to blend.
Place a Parmesan cup on each of 4 plates. Divide the roasted cherry tomatoes equally among the cups and serve immediately.
Per serving: 173 calories, 10 g protein, 4 g carbohydrates, 1 g fibre, 14 g total fat, 5 g saturated fat, 20 mg cholesterol, 394 mg sodium