Preheat the oven to 400°F (200°C).
On a baking sheet, toss the halved cherry tomatoes with olive oil, minced garlic, oregano, red pepper flakes (if using), salt, and pepper.
Roast the tomatoes in the oven for 15-20 minutes, or until they are soft and slightly caramelized.
While the tomatoes are roasting, heat a skillet over medium heat and lightly sauté the spinach until wilted, about 2-3 minutes. Remove from heat and set aside.
Once the tomatoes are done, remove them from the oven and set aside.
Place the flatbread on a baking sheet and sprinkle with mozzarella and parmesan cheese.
Distribute the roasted tomatoes and wilted spinach evenly over the cheese on the flatbread.
Return the flatbread to the oven and bake for another 5-7 minutes, or until the cheese is fully melted and the edges of the flatbread are crispy.
Remove from the oven, slice, and serve hot.