Defrost spinach at room temperature. Peel onion and cut into fine cubes. Clean, wash and halve the tomatoes. Wash meat, dab dry, season with salt and pepper and top with chorizo, half spinach and cheese.
Fold up the meat and fix it with wooden skewers. For the spinach, heat 1 tablespoon of fat. Sauté the onion until translucent. Add the spinach, pour in 100 ml broth, bring to the boil and simmer for about 10 minutes.
After 7 minutes add the tomatoes. Season to taste with salt and nutmeg. Heat oil in a frying pan. Fry meat for 7-10 minutes, turning. Heat 1 tablespoon of fat in a second pan and fry the spaetzle.
Season with salt and pepper. Remove meat from the pan and keep warm. Add sherry and 100 ml broth, bring to the boil and reduce by half. Arrange meat, spaetzle and vegetables with the roast jus on plates.