01 - Rinse strawberries thoroughly, remove hulls, and cut in half. Arrange strawberry halves evenly in a rectangular mold or loaf pan (approximately 8 x 4 inches).
02 - In a small saucepan, combine whole milk, granulated sugar, and powdered agar-agar. Whisk vigorously until agar-agar is completely dissolved and no lumps remain.
03 - Place saucepan over medium heat and bring mixture to a gentle simmer, stirring constantly. Maintain simmer for 2 minutes to fully activate the gelling properties of the agar-agar.
04 - Remove from heat immediately and stir in vanilla extract until fully incorporated.
05 - Let milk mixture cool for 2 to 3 minutes, then gently pour over arranged strawberries in the mold. Lightly tap mold on counter to release air bubbles and distribute strawberries evenly. Allow to cool to room temperature.
06 - Refrigerate for at least 3 hours or until completely firm and set throughout.
07 - Once fully set, unmold onto cutting board and slice into rectangular portions. Garnish with fresh mint leaves if desired.