Preheat your oven to 400 degrees F and, if using store/previously prepared pie crust, ensure that one sheet is thawed.
In a small bowl, mix the ricotta, the juice and zest of one lemon, the yolk of the egg (reserve the white for later), the salt, and 3 tablespoons of the sugar. Set this mix aside.
In another small bowl, sprinkle the blueberries with an additional tablespoon of sugar. Spread out your halved figs and likewise sprinkle them with about a tablespoon of sugar.
Now you're ready to assemble your tart. On a greased sheet pan, unroll your crust to form a rough oval or circle. Spread this with the ricotta mixture, leaving at a 1-1.5 inch border around the edge (you'll be folding up the tart). Sprinkle half of the blueberries over the ricotta, then distribute your figs evenly, then sprinkle the other half of the blueberries. Fold up the edges of the tart just to cover the sides. I like to fold in on the left and right, form corners, then fold up the top and bottom. But this is rustic--fold gently however you like so that the cheese and berries won't leak onto the pan.
Find your reserved egg white, mix it with a tablespoon of water or milk, and brush the sides of the tart. Sprinkle this with the final tablespoon of sugar, and bake for 25-35 minutes or until golden brown and the berries are beginning to bubble.