Sweet Rhubarb Tarts

Put approximately 1 3/4 cups flour in a bowl. Heat milk until lukewarm in a small pot.

Crumble the yeast into the lukewarm milk, add sugar and stir until both are dissolved.

Melt the butter in another small pot and allow to cool slightly.

Rinse the lemon in warm water and wipe dry. Finely grate the zest. 

Add the lemon zest to the flour along with the yeast-milk mixture, butter and 1 pinch of salt. Knead with the dough hook of a hand mixer to a smooth, elastic dough.

Cover with a kitchen towel and let rise in a warm place until the dough doubles in bulk, about 30 minutes.

Meanwhile, rinse rhubarb, pat dry and cut into thin slices. Place in a bowl and add sweetener to taste.

Halve vanilla bean lengthwise, scrape out the seeds and stir with the yogurt in a small bowl until smooth. Add sweetener to taste and refrigerate.

Knead the dough with your hands briefly. Divide into 12 pieces, place on a floured work surface and roll out the dough to disks, each about 5 inches in diameter.

Line a baking sheet with parchment paper. Arrange the disks on it and cover evenly with rhubarb.