Wash lemon hot, dry. Finely grate the peel. Squeeze lemon. Peel onion and garlic, dice finely. Fry in 1 tbsp. hot butter. Deglaze with wine or about 1/8 l water and cream.
Bring to the boil and simmer for about 5 minutes. Melt the mascarpone in the sauce. Stir in lemon peel. Season to taste with 2-3 tablespoons lemon juice, salt, pepper and sugar. Bind with sauce thickener, bring to the boil.
Clean, wash and possibly pluck the arugula smaller. Wash the basil, pluck the leaves. Cook the pasta in boiling salted water for about 10 minutes.
Dab meat dry and cut into thin medallions. Fry in hot oil in portions on each side for about 1 minute. Season with salt and pepper and remove. Heat 2 tablespoons of butter in the frying fat.
Add 1-2 tablespoons lemon juice. Swivel the meat in it. Drain the noodles. Mix with rocket, basil and sauce. Arrange medallions and garnish with lemon. Drink tip: cool white wine, e.g. Pinot Grigio.