Halve the cherry tomatoes, place them on a tray with the cut surface facing up and sprinkle with a little powdered sugar and a little oregano. Bake in the middle of the oven preheated to 130 ° C for about 45 minutes.
Bring the washed lentils with the bay leaf and garlic to the boil in water (the lentils should just be covered), cover and simmer on a low fire for about 30 minutes, depending on the variety.
Mix the balsamic vinegar, broth, mustard, salt and pepper well and mix with the olive oil to a creamy sauce. Add the onions and parsley. Drain the lentils and mix with the sauce while hot.
Arrange the lentils on 4 plates. Spread the still warm baked tomatoes on top and grate the parmesan cheese over it.