n a large saucepan, combine frozen strawberries, frozen rhubarb, undrained can of crushed pineapple, and sugar.
Bring to a boil over medium-high heat, stirring frequently.
Reduce heat and simmer for 15 minutes. Continue to stir occasionally.
Using a spoon or potato masher; crush strawberry and rhubarb pieces and continue to simmer for 5 minutes.
Remove from heat; stir in strawberry gelatin until dissolved. Stir until gelatin is completely dissolved and there are no more granules in the mix.
Ladle jam into half pint canning jars or freezer containers. If you are going to properly can this jam, you'll want to leave about 1/2-inch headspace at the top between the jam and the lid.
Cool completely. Refrigerate or freeze.
Notes
This recipe can easily be doubled to make more.
I use frozen fruit for this, but you can also use fresh if you want. We go strawberry picking early in the season and I end up freezing quite a bit so I can make this jam later.
If you are purchasing frozen strawberries, make sure you get unsweetened strawberries. this is really important as they can both be right next to each other on the freezer shelf.
This needs to cool completely to set up properly. Leave in the refrigerator for about 24 hours for it to completely set up.