Put mashed tomatoes in a saucepan.
Add olive oil, Provencal herbs and salt to taste. Put on fire and heat, but do not boil.
Cut the baguette into slices.
Put on a baking sheet.
Spread the grated tomatoes with cooked sauce. Let stand for 2-3 minutes.
Sprinkle with grated cheese and place in an oven preheated to 200 degrees C for 3-5 minutes.
Take out and cool.
Place on a platter and garnish with finely chopped onions.