Preparation Put oven rack in middle position and preheat oven to 425°F. Prepare compote: Stir together sugar and potato starch, then gently toss with strawberries, rhubarb, lemon juice, and zest. Transfer mixture to an ungreased shallow 3-quart (13- by 9- by 2-inch) baking dish. Make topping and bake: Whisk together matzo cake meal, brown sugar, potato starch, cinnamon, and salt in a bowl. Blend in butter with your fingertips until mixture forms small clumps. Crumble streusel evenly over top of compote and bake until fruit is bubbling and topping is golden, 40 to 45 minutes. Cool to warm on a rack before serving.
Preparation Put oven rack in middle position and preheat oven to 425°F. Prepare compote: Stir together sugar and potato starch, then gently toss with strawberries, rhubarb, lemon juice, and zest. Transfer mixture to an ungreased shallow 3-quart (13- by 9- by 2-inch) baking dish. Make topping and bake: Whisk together matzo cake meal, brown sugar, potato starch, cinnamon, and salt in a bowl. Blend in butter with your fingertips until mixture forms small clumps. Crumble streusel evenly over top of compote and bake until fruit is bubbling and topping is golden, 40 to 45 minutes. Cool to warm on a rack before serving.