Make the tart shells:

• In a food processor, pulse flour, powdered sugar, and salt. Add butter and pulse until crumbly. Add egg yolk and cold water, 1 tablespoon at a time, just until the dough comes together.

• Form dough into a disk, wrap in plastic, and chill for 30 minutes.

• Roll out dough and press into mini tartlet pans (about 6–8 depending on size). Prick the bottoms with a fork. Chill for 15 more minutes.

• Preheat oven to 375°F (190°C). Bake tart shells for 12–15 minutes or until golden. Cool completely.

Prepare the strawberry puree:

• In a small saucepan, combine strawberries, granulated sugar, and lemon juice. Cook over medium heat until strawberries break down, about 5–7 minutes.

• Remove from heat and puree the mixture with a blender or immersion blender. Let it cool completely.

Make the mousse:

• In a bowl, beat cream cheese with powdered sugar and vanilla until smooth.

• In a separate bowl, whip the heavy cream until stiff peaks form.

• Fold the cooled strawberry puree into the cream cheese mixture, then gently fold in the whipped cream until smooth and fluffy.

Assemble tartlets:

• Spoon or pipe the strawberry mousse into the cooled tart shells.

• Chill for at least 1 hour before serving to set the mousse.

• Garnish with sliced strawberries, mint, or whipped cream if desired.