1. Remove any damaged leaves from the endives. Rinse, drain, and pat dry immediately.
2. In a pressure cooker, heat the margarine and add the endives. Let them brown on all sides.
3. Peel the garlic and onions, then finely slice them. Squeeze the half lemon and collect its juice.
4. Add the garlic, onions, lemon juice, salt, and pepper, then close the pressure cooker.
5. Let simmer on low heat for 20 minutes from the moment the pressure valve turns.
6. Release the steam and serve immediately. Enjoy the braised endives with onions.
7. Release the steam and serve immediately. Enjoy the braised endives with onions.