Set the temperature of the oven to 175 C (350 F).
In a bowl, mix sliced strawberries, lemon juice, sugar and cornstarch. Mix until the strawberries are thoroughly mixed.
Pour the mixture into a greased 8 X 8-inch baking sheet or oven-safe dish of same size.
In a separate bowl, mix the rolled oats, brown sugar, flour and salt and cinnamon.
Add the cubed butter and using your finger or a pastry cutter mix until it resembles coarse crumbs.
Now, evenly spread the crumbled topping over the strawberry filling.
Now, bake it in the oven until the strawberries are bubbly and the topping turns golden brown, it may take around 30-25 minutes.
Before serving, let the crumble cool a bit. You can serve it with a scoop of vanilla ice cream.