Swiss-Style Meatballs with Potato Salad

For the meatballs: Tear the bread into bite-size pieces, place in a bowl and soak in lukewarm water. Peel the onion and garlic and chop finely. Heat 1 tablespoon oil in a skillet and saute the onion and garlic until translucent. Rinse the rosemary, shake dry, strip off the needles, finely chop and mix with the onion. Remove from heat and let cool. Rinse and quarter the tomatoes, remove the seeds and cut into small dice. Set aside one-third of the tomatoes. In a bowl, mix the ground beef with the egg, mustard, onion mixture, the well-squeezed bread, two-thirds of the tomatoes, and season with salt and pepper. Knead to combine, shape into small meatballs, cover and refrigerate 30 minutes.

For the potato salad: Scrub the potatoes and cook in a pot of boiling salted water until knife-tender, about 25 minutes. Drain, rinse with cold water, drain well, peel and let cool.

Heat the milk and butter in a saucepan, stir in the mustard and add the freshly grated cheese. Cook, stirring until the sauce is lightly thickened and season with salt and pepper. Cut the potatoes into slices, place in a bowl, pour the sauce over it, carefully fold, season with salt and pepper and let stand for about 15 minutes.