So this is a dessert I was making for "non-paleo" family members, so I added more sugar then I would have if it had just been for us. So adjust the amount of sugar/honey to your taste. This may seem quite sweet but was great for non-paleo taste buds! This was also quite a large batch and could serve 8 adults, so you may want to split it in half if you're just doing it for a family of four. That's partly why I left the measurements in tablespoons, so it would be easier to adjust the size.
Topping:
6 tbsp arrowroot flour
6 tbsp almond meal
6 tbsp coconut sugar
2 tbsp pecans
2 tbsp walnuts
1/2 tsp salt
drizzle of honey (to taste, ~ 1-2 tsp)
Process all of the above in food processor until it's like a dough, then mix in by hand:
1 cup coarsely chopped pecans
1 cup coarsely chopped walnuts
Filling:
4 cups cut up rhubarb
4 cups cut up strawberries
1/3 cup honey
2 tbsp arrowroot flour
1 tbsp lemon juice
Mix all the filling together and pour into a pyrex dish, then spread the crumble topping over the top. Bake at 400'F for 25 minutes, or until the topping is brown.