Bring 3-4 l salted water (1 teaspoon salt per litre) to the boil. Wash and drain the spinach. Cut the bell peppers into fine strips. Peel and finely chop onion and garlic.
Cook the pasta in boiling salted water according to the instructions on the packet. Meanwhile heat the oil in a pot. Sauté onion and garlic. Deglaze with milk and 150 ml water, bring to the boil. Stir in stock, simmer for about 5 minutes. Stir in ricotta. Add paprika and spinach, let spinach collapse for a short time. Season sauce with salt, pepper and nutmeg.
Roughly chop the cashews. Drain the pasta and mix with the sauce. Sprinkle cashews over it.