Apple Puff Pastry Tart with Yogurt Cream Filling

Ingredients:

2 sheets of puff pastry (each 250 g / 8.8 oz)
1 teaspoon sugar (for dusting each puff pastry sheet)
3 apples, peeled, cored, and sliced
3 tablespoons butter (90 g)
2 tablespoons sugar (45 g)
2 cups yogurt (480 g)
1 cup heavy cream (240 ml / 8 fl oz)
3 tablespoons condensed milk (90 g)
1 tablespoon agar agar (10 g / 0.35 oz)

Directions:

Prepare the first puff pastry layer: