Preheat the oven to 400 degrees . Unroll the piecrust and press it into a 9-inch tart pan. Prick the bottom of the dough all over with a fork, brush with the 1 tablespoon of olive oil, sprinkle with salt and pepper and bake for 10 minutes.
In a medium bowl, stir together the ricotta, blue cheese and egg until combined. Remove the tart shell from the oven and immediately prick with a fork in a few places. Spoon the cheese mixture into the tart shell and top with the tomato slices; season with pepper and bake for 25 minutes. Remove the tart from the oven and let cool slightly.
In a large bowl, toss the salad greens with olive oil, lemon zest, lemon juice and salt to taste. Cut the tart into wedges and serve with the greens.