Peel and slice the potatoes. Brush a baking sheet generously with oil and distribute the potato slices evenly. Cut the tomatoes and the onion into slices and distribute them again on the potatoes. Salt and pepper everything and drizzle a little oil over it. In the oven at 220 degrees and after about 30 minutes put the seasoned lamb chops (with salt, pepper or marinade) on top. Bake for another 10-15 minutes, depending on the thickness of the chops. Serve on the tray.