Thaw spinach (either during the day or in the microwave). Cook the tortellini according to the instructions on the packet and drain in the sieve.
Dice the onions, chop the garlic and fry in oil in a large pan until both are translucent. Add pickled tomatoes if you like. Chop the tomatoes and add them together with the spinach leaves. Bring to the boil and add 100 g of ricotta. Season to taste with salt and pepper, add a little Parmesan cheese if you like.
Add the drained tortellini and mix. If necessary, wait a moment until the tortellini are completely warmed up again.