Put the flour, sugar, salt and butter in a medium bowl. Crumble the mixture between your fingers until it looks like breadcrumbs.

Preheat oven at 400 F.

Wash fruit and cut the biggest in pieces (if you use frozen fruit you do not need to defrost them). Put them in an oven dish, sprinkle lemon zest and evenly cover all the fruit with the crumble mixture.

Put in the oven for 30 minutes until lightly golden and let it cool.