1. Wash the oranges and lemon well when they are used. You can choose thin-skinned oranges for a smoother jam or thick-skinned oranges if you like the texture of the skin pieces in your jam.

2. Peel the oranges and lemon and try to remove most of the inner white part of the peel as it can be bitter. Cut the shells into thin strips if you want them to be present in the jam.

3. Cut the peeled oranges into small pieces, removing as many seeds as possible.

4. Place the oranges in a large saucepan and add enough water to cover them. Bring to a boil and cook over medium heat for about 40 minutes, or until the oranges are soft and the mixture is reduced.
5. Add the orange peel strips, if using.

6. Add the sugar to the pan and stir well so that it dissolves completely.

7. Squeeze the juice of the lemon and add to the mixture. Lemon not only improves acidity, but also promotes gelling ability thanks to its natural pectin content.

8. Cook the mixture over medium-low heat for about 30-40 minutes, stirring occasionally so it doesn’t stick to the bottom of the pan. The jam should thicken as it cooks and become more translucent.

9. To check the consistency, put a small amount of jam on a cold tray and wait a few minutes to see if it gels. If so, the jam is ready. If not, continue cooking and repeat the test every few minutes.

10. Once the jam has reached the desired consistency, remove the pan from the heat and let the mixture cool for a few minutes.