Cut the cleaned and washed endive salad into strips. Sweat the diced onions in a little butter. Add the salad and cook for a few minutes. Take out of the pan.
Reduce the cream and the grated Parmesan in the pan until creamy, then add the onion and endive mixture again and season with salt, pepper and lemon juice.
In the meantime, prepare the tortellini in salted water according to the instructions on the packet. Drain and mix into the endive and cream sauce.