Rhubarb, strawberry, apple jam

Made this jam for the first time, Rhubarb, strawberry, apple jam. Love the flavor 💕🍓🍏 thanks to my friend and super talented chef for the recipe.

Mix 1 kg rhubarb (cut in bite size), halved 500 g strawberries, 800g sugar and 10 g salt. Cook in a large pot on med high, stirring for abut 15 min. Add cut cored 1 large apple, juice and zest of 1 lemon, continue cooking. When it will start creating a foam add some butter and take out the foam. Preserve is ready when get deeper in color.