Cut the ham in half crosswise. Dab roulades dry, season with salt and pepper. Spread with pesto, sprinkle with parmesan, cover with 1/2 slice of ham and roll up. Fix the roulades with wooden skewers.
Heat 2 tablespoons of oil in a large, coated frying pan. Fry the roulades vigorously on all sides. Peel and roughly dice the onions. Add the tomato paste to the roulades and fry for 2-3 minutes.
Pour the wine and bouillon into the roulades, bring to the boil and cook for at least 1 hour. Wash the marjoram and dab dry. Put some stems aside for garnishing. Pluck the rest of the marjoram from the stalks and chop the leaves roughly.
Clean, wash and cut the zucchini into pieces. Wash and halve the tomatoes. Peel red onion and garlic and cut into rings or slices. Put the dumplings in boiling water, take the pot off the stove and let it simmer for about 7 minutes.
Heat 1 tablespoon of oil in a frying pan. Fry the zucchini for about 2 minutes. Add onion, garlic and tomatoes and fry for about 4 minutes. Fold in chopped marjoram and season with salt and pepper.
Remove the roulades from the sauce and keep warm. Reduce the sauce if necessary. Stir the starch with a little water until smooth and thicken the simmering sauce slightly. Season to taste with salt and pepper. Arrange roulades, dumplings, vegetables and sauce on preheated plates and garnish with the remaining marjoram.