Preheat broiler to high; position oven rack in the upper 1/3 of the oven.
Heat oil in a medium saute pan over medium-high heat. Add sliced zucchini and saute for 1-2 minutes to soften slightly. Add garlic, red pepper flakes, and herbs and toss to coat, cooking for another 1-2 minutes or until garlic is fragrant and zucchini is tender.
In a bowl, stir together ricotta, lemon zest, salt and pepper to taste.
Arrange flatbreads on a sheet pan. Brush lightly with olive oil. Divide zucchini mixture among flatbreads, spreading evenly atop the bread. Drop dollops of ricotta mixture on top. Sprinkle with a pinch of sea salt and a twist of black pepper.
Broil flatbreads for 2 to 3 minutes or until cheese melts and bread browns on the edges. Remove from oven and let cool slightly, then slice and serve warm.