Fill the cooled tart crust with the hot jam (or if cool, warm the jam in a small skillet until easily spreadable. Set aside.
Whisk the milk and agar agar into a small saucepan set over high heat. Continue whisking and bring to a boil. Once boiling, turn the heat down to simmer for 5 minutes, whisking the whole time. Pour the hot yogurt into the tart, onto the jam carefully. Chill for 5 minutes.
Remove the tart from the refrigerator and top with fresh fruit such as tiger figs, blackberries, and raspberries. Chill overnight before serving.