In the bowl of the Mini Mixer fitted with the flat paddle, whisk together flour, salt, lavender flowers, and sugar. Add butter cubes and toss to distribute evenly. Mix on medium-low speed until the mixture looks like coarse sand. Add water and mix on low until the dough pulls together. Remove dough from mixer and shape into a ball, then flatten into a ½-inch thick disk. Wrap with plastic and refrigerate for at least half an hour.

While the dough chills, make the lavender sugar. Place ¼ cup sugar and 2 teaspoons lavender in a food processor or spice grinder and pulse until the lavender flowers are finely ground and the sugar is fragrant (15-30 seconds). In a large bowl, mix blueberries, lavender sugar, lemon juice, lemon zest, vanilla, and sea salt until blueberries are thoroughly and evenly coated. Add cornstarch and toss until it’s dissolved evenly throughout. In a separate, small bowl, whisk the egg for the egg wash, and set aside.

Preheat oven to 400º and line a rimmed baking sheet with parchment paper. Once dough has chilled, move the parchment paper to a flat surface and roll the dough out into a rough circle, ¼-inch thick. Transfer back to baking sheet, and spread blueberry filling in the center of the dough, leaving a 2-3-inch perimeter around the edge.

Fold the edges of the dough in, layering and crimping sections as you go. Make sure there are no tears or gaps (to prevent excess leaking). Brush the dough with egg wash. Bake for 30-35 minutes, until the top is golden brown and the bottom is starting to caramelize. Let cool on a wire rack at least 25 minutes before serving.

While it cools, place whipping cream and honey in the (cleanebowl of the Mini Mixer and fit it with the whisk attachment. Mix on high until soft peaks form. Keep chilled until ready to serve.

Serve slices of galette topped with whipped cream, a sprinkle of lemon zest, and a few lavender flowers.