This rustic dessert has a flaky, nutty, biscuitlike topping and lots of sweet, juicy fruit. Look for rhubarb, an edible plant, in the markets during spring and summer months. Be sure to trim away and discard any green parts before using.
Preheat oven to 375°F (190°C). Spread pecans in a single layer on a baking sheet and toast in oven until lightly browned, 5–8 minutes. Remove from oven and let cool slightly, then chop coarsely and set aside. Leave oven on.