In the bowl of a food processor, blend flour, sugar, and salt. Add butter pieces and pulse using on/off turns until the mixture resembles coarse meal with pea-size pieces of butter. Add two tablespoons ice water; blend just until moist clumps form, adding more water by teaspoonfuls if mixture is dry. The trick is to not overwork the dough, you want little bits of butter distributed throughout the dough, that's what will give it a flaky texture. Gather dough into a ball and softly flatten into a disk. Wrap dough in plastic wrap and refrigerate for at least 20 minutes.

Remove the dough and transfer to a cold surface lightly coated with flour, a clean marble counter works great for this. Gently press the dough into a 4-inch disk. Wrap in plastic wrap and refrigerate for an additional 20 minutes.

Preheat oven to 350°F. Unwrap the chilled dough and place on a piece of parchment paper. Dust the dough lightly with flour. Cover the dough with another piece of parchment paper and roll into a circle. Carefully peel off the top piece of parchment paper, and transfer the dough along with the bottom piece of parchment onto a rimmed baking sheet.

For the filling, in a medium size bowl, whisk together almonds, cornstarch, and ¼ cup of sugar. Spoon the mixture onto the prepared pastry. Be sure to leave about a 2-inch border around the edge of the pastry. Use the same bowl to combine the strawberries and almond extract if desired. Spoon the berries carefully on top of the almond mixture.

Using a bench scraper, carefully fold the edges of the pastry up and over the strawberry filling. If any rips form, gently pinch with your fingers to seal.

In a small bowl, whisk together the egg yolk and milk; whisk to combine. Use a pastry brush to lightly coat the edges of the galette with the egg wash (this makes it shiny and golden; if you have egg or milk allergies it won't change the flavor if you leave these out). Lightly sprinkle the edges of the pastry with Turbinado sugar.

Bake for 55 minutes, until the pastry is golden brown and the strawberry juices are bubbling. Cool for 15-20 minutes before slicing. Serve with whipped cream or vanilla ice cream.