If you're using instant clearjel, cook the frozen fruit and lemon juice on medium heat until the berries are fully thawed and the liquid begins to simmer.
Using a sturdy spatula, cut any large berries into very small pieces as they simmer. The berries should be soft enough that they are easy to cut with the spatula.
Cook for about 5 minutes or until the berries are softened and you are happy with their size. Remove from heat and immediately add the instant clearjel mixture and stir in quickly until it dissolves.