Place the tomatoes on a sheet pan and drizzle with a few tablespoons of olive oil. Season with salt and pepper. Roast in the oven until the tomatoes begin to collapse and release some of their juices, about 15-20 minutes.
Preheat the broiler to high and arrange an oven rack to the highest position.
On another baking sheet, arrange baguette slices. Drizzle each side lightly with olive oil. Broil, flipping once, until the baguette slices are lightly toasted. Remove from the oven and immediately rub each slice with the cut side of the garlic.
To prepare the toast, top each slice of baguette with a thick layer of pesto, a few roasted tomatoes, and a few shavings of Parmesan cheese. Serve immediately.