4tablespoonunsalted butter(generally rubs in easiest if cold)
Instructions
Preheat the oven to 375F/190C. Lightly grease either 4 individual pie pans/dishes or a medium baking dish (approx 11-12in x 7-8in (28-30cm x 18-20cm) and at least 1 in (2.5cm) deep). If the pie dishes are non stick, as mine are, then you can skip greasing them.
Trim the ends then cut the rhubarb into short lengths around ½ inch/ 1.5cm long. Remove the stems from the strawberries and cut in half/quarters (or smaller, if large) so that all of the fruit pieces are of similar size.
Place all of the fruit in a bowl, add the lemon zest and juice, corn starch and sugar. Toss to combine well, then divide evenly between individual dishes, or pour into the larger dish.
For the topping, mix together the oats, flour, brown sugar and cinnamon. Cut the butter into small pieces and rub into the flour mixture so that you get coarse crumbs. Divide the mixture between the dishes, covering the fruit relatively evenly. Place the dish or dishes on a baking sheet/tray to catch any drips.
Bake for approx 35 minutes until the fruit bubbles up around the side and the topping is gently browned. Allow to cool slightly before serving. I'd recommend topping with ice cream (cream/creme fraiche also good).