Preheat the oven to 200°c.
Place the chopped rhubarb into an oven proof dish and sprinkle over 2 tbsp. of the stevia.
In a large bowl, mix together the oats, ground almonds, flax, nuts and remaining stevia.
Pour the coconut oil over the dry mix and mix well with your hands into a crumbly texture.
Sprinkle the crumble mix over the fruit.
Bake for 30 around minutes or until the topping is crunchy and golden.
Serve with a dollop of Greek yoghurt.