Peel and finely dice the onion and garlic. Heat 2 tablespoons of oil in a saucepan. Sauté onion and garlic in it. Add frozen spinach and 100 ml water, season with salt and pepper. Bring to the boil and defrost at low heat.
For the Saltimbocca, meanwhile, wash the sage and shake dry. Wash the meat, dab dry and cut a pocket into each. Fill with 1 slice of ham and 2-3 sage leaves. Pin them down. Season with salt and pepper.
Cook the pasta in boiling salted water according to the instructions on the packet. Heat 2 tablespoons of oil in a frying pan. Fry Saltimbocca in it for about 6 minutes on each side. Fry the rest of the sage briefly. Deglaze everything with wine and keep warm.
Stir the crème fraiche into the spinach. Season to taste with salt, pepper and nutmeg. Drain the pasta, drain and mix with the spinach. Serve with Saltimbocca and possibly roast.
Cut the chicken filet deep inside, but not quite through at the ends and back. This is best done with a sharp, pointed knife.