In a large, heavy-bottomed pot, combine the chopped rhubarb, sugar, chopped orange (with or without peel), crushed pineapple, and chopped strawberries if using. If your mixture seems too dry or you're worried about the sugar scorching, add up to 1/2 cup of water to help dissolve the sugar.

Let the fruit and sugar mixture sit for about 15-30 minutes to macerate, which helps the sugar dissolve and draws out the juices from the fruit.

After macerating, add the lemon juice and bring the mixture to a boil over medium heat, stirring frequently to prevent sticking.

Reduce the heat and simmer for 15-20 minutes, or until the rhubarb is tender and the mixture has thickened. If you're using pectin, add it according to the package instructions, usually after the fruit has softened.

To test if the jam is set, place a small spoonful on a cold plate. If it firms up after a few minutes in the fridge, it's ready. If it's too runny, continue cooking for a few more minutes and test again.

Sterilize your jars and lids by boiling them in water for 10 minutes.

Pour the hot jam into the sterilized jars, leaving about 1/4 inch of headspace. Wipe the rims clean, then seal the jars with the lids and rings.

Process the jars in a boiling water bath for 10 minutes to ensure a good seal and to make the jam shelf-stable.

Once cooled, check the seals, and then store the jars in a cool, dark place for up to a year. Any jars that haven’t sealed properly should be refrigerated and used within a few weeks.