Blend together chopped rhubarb, strawberry, ½ cup sugar, cornstarch, and ¼ cup flour.
Pour into a buttered 10-inch oven safe skillet, and heat over medium for 10 minutes, stirring occasionally, until thickened. Set aside.
In a bowl, stir together 1 cup flour, rolled oats, sugar, cinnamon and water. Then cut in butter with a pastry cutter or two forks until you have a crumbly, slightly moist texture.
Sprinkle topping to cover your filling, then bake uncovered at 350F degrees for 35-40 minutes. If you notice the topping getting too dark, cover with aluminum foil.
Cool for 10 minutes before serving.
Notes
Please refer to my FAQ’s and ingredient list above for other substitutions or for the answers to the most common questions.
If you don't have an oven safe skillet, you can cook the filling first on the stove then add it into a 9x9-inch baking dish and continue with the rest of the recipe
When working with fresh rhubarb, the leaves are toxic to humans and animals so please discard with care. They are not good to go into any compost pile.