Put quinoa in a very fine sieve and rinse with very hot water. Bring 600 ml of water and quinoa to the boil, cover and simmer over a low to medium heat for about 15 minutes. Remove from the heat and let it simmer for about 5 minutes.
Remove the lid, loosen the quinoa with a fork.
In the meantime peel and finely dice the onions. Peel garlic and chop finely. Clean and wash the chard, remove 125 g chard and chop finely. Cut the remaining chard roughly into strips. Grate Parmesan finely.
Clean, wash and halve the tomatoes. Put quinoa, about 1/2 onion, 1 teaspoon salt, 1 teaspoon pepper, about 1/2 garlic, parmesan, finely chopped chard and eggs into a mixing bowl and knead well.
Form approx. 12 meatballs (each approx. 2.5 cm high) from the mixture.
Heat clarified butter in portions in a large pan, fry the meatballs in it in portions on each side for 2-3 minutes, remove and keep warm. Heat the oil in a large pan, fry the tomatoes briefly and remove.
Add remaining onions and garlic and fry until transparent. Add chard and fry for 3-4 minutes, turning. Season to taste with salt, pepper and nutmeg. Carefully mix in the tomatoes. Arrange vegetables and meatballs on plates, garnish with a spot of sour cream.