Combine flour, white sugar, salt in food processor.
Add cold butter cubes, pulse for a few minutes until the mixture is crumbly. Pour in ice water. Mix. Gently knead everything together until a dough forms.
On a lightly floured surface, start shaping the dough into a small ball, then flatten it into a thick, disc-like shape. Wrap it up in cling film, and let it chill in the fridge for 30-40 minutes.
Meanwhile cut the strawberries: large ones into quarters and smaller into halves. Set aside.
When 40 minutes have passed, preheat the oven to 350F.
Place a piece of parchment paper on your workspace (it needs to be the same size as your baking tray) and with a rolling pin, roll out the dough into a circle, roughly about 11 inches in diameter. If you want perfectly even edges, feel free to use a dinner plate as a guide. Cut around it and gently transfer the dough onto the baking tray lined with wax or parchment paper.
Together with the parchment paper, transfer the dough onto a baking sheet. Lightly dust the center of the galette with cornstarch.
Strawberry filling. Arrange sliced strawberries on top of the dough center, leaving about a 2 inches border all around. Sprinkle the strawberries with 1 tablespoon of white sugar. And gently fold the edges over the fruit. Press gently to secure the filling. If you see any holes occurring, try to pinch them dough to close them.
Brush the edges of the galette with egg yolk and sprinkle it with 1 tablespoon brown sugar (or you can use less or omit the sugar entirely). Bake for approximately 40-45 minutes or until the crust turns golden brown. Let the galette rest and cool for 10-15 minutes and generously brush with your favorite jam. I like to use strawberry rhubarb jam.
Garnish with fresh mint leaves and serve with a scoop of vanilla ice cream. To balance the sweet flavors, you can add lemon zest onto of strawberries before baking or drizzle the baked galette with a touch of lemon juice.