Preheat the oven to 350 f / 175 C. I use a springform pan so I lined it with parchment paper. If not using a springform pan, skip this step. Pan measurements are 9 inch (23 cm) round cake pan or an 8 inch (20 cm) square pan.
Place the chopped strawberries, rhubarb, sugar, lemon zest and cornstarch in a large bowl. Mix well and set aside while you prepare the crisp topping.
In a separate bowl, combine the flour, oats, almonds, white and brown sugar, salt and cinnamon. Chop the cold butter into cubes and add it to the bowl.
Using your hands, fork or a pastry cutter, smash the butter into the dry ingredients until you get a pea-sized crumbles.
Transfer the fruit filling to your baking pan. Sprinkle the crisp topping over the filling. Don’t press it down to ensure that the topping remains light and crisp and steam can escape.
Bake for 45 to 55 minutes or until the topping in golden brown and the filling is bubbling up around the edges.
Allow the crisp to cool for at least 30 minutes to give the filling time to thicken up.