- Preheat the oven to 350°F.
- To make the dough: Whisk together the all-purpose flour, almond flour, sugar, and salt in a mixing bowl. Work the cold, diced butter into the flour between your fingers until the mixture has the consistency of sand. Add the milk and mix with a fork until a wet, crumbly dough is formed.
- Press 2/3 of the dough into a 4 1/4" x 13 3/4" rectangular tart pan, starting at the bottom and working the dough up the sides. Reserve the remaining dough for the topping.
- Chill the tart dough in the pan and the remaining 1/3 for the topping for 30 minutes.
- For the filling: Toss together the strawberries, sugar, cornstarch, vanilla seeds, and lemon juice in a bowl and let rest at room temperature while the dough chills.
- Fill the tart crust with the strawberry mixture and crumble the reserved dough on top. Sprinkle with the sliced almonds.
- Place the tart on a baking sheet to catch any butter that seeps out during baking. Bake the tart for 45 to 50 minutes, until it's golden brown. Remove it from the oven and let the tart cool before slicing.
- Store any leftovers in the refrigerator, well wrapped, for several days. Freeze for longer storage.