Preheat the oven—and a baking sheet—to 190°C (375°F). In a medium bowl, combine the diced rhubarb and strawberries. Add the cornstarch, sugar and lemon zest on top. Don’t mix just yet—the fruit might release too many juices before you’re ready to fill the galette.
On a well-floured surface, roll out the pie crust to about ¼ inch thick. Transfer it to a piece of baking paper. Gently toss the filling ingredients to combine.
Pile the filling in the center of the crust, leaving a rim around the edge. Spread it evenly. Fold up the edges and crimp them gently around the fruit. Pinch any seams closed to help prevent leaks.
Brush the crust with egg wash and press on the flaked almonds. Optional: sprinkle 1–2 tbsp sugar over the top.
Bake for 40–45 minutes, or until the crust and almonds are golden and the filling is bubbling. Let cool completely before slicing so the juices can set.
Notes
If you're worried about the galette holding its shape, chill it in the fridge or freezer for 15 minutes before baking.
If the crust or almonds brown too quickly, cover the edges with foil and continue baking.
For a spicy twist on a classic, add ½ tsp freshly grated ginger (or 1 tsp ground) to the filling.
If you prefer tart desserts, reduce the sugar to ½ cup. It makes the lemon sing!
Any grain or flour will work for the crust. I used spelt here, but it’s delicious with fresh-milled or store-bought flour of your choice.