In a large mixing bowl, combine 1 ½ cups of flour, ½ cup of cold butter, and ¼ cup of sugar. Use a pastry cutter or your fingers to mix until crumbly. Press evenly into the tart pan. Bake at 350°F (175°C) for 15–20 minutes, or until golden.

While the crust is baking, whisk together 3 large eggs and ½ cup of sugar until smooth. Add ⅓ cup of fresh lemon juice and 1 tablespoon of culinary-grade lavender, whisking until combined.

Once the crust is slightly cooled, pour in the filling and bake at 350°F (175°C) for 25–30 minutes, until edges are set and center is slightly wobbly.

Remove the tart and let it cool on a wire rack for about 1 hour. Chill in the refrigerator for at least 2 hours, preferably overnight.

Before serving, garnish with edible flowers or additional lavender. Cut into wedges and serve chilled.