Preheat your oven to 425°F (220°C).
In a small bowl, whisk together the tomato paste, Italian seasoning, olive oil and water until well combined. This is the pizza sauce.
Place the flatbread pieces on a baking sheet lined with parchment paper. Spread a layer of pizza sauce evenly over each piece of flatbread, leaving a small border around the edges.
Place four slices of mozzarella cheese over the sauce on each flatbread. Arrange the thinly sliced Roma tomatoes on top of the cheese. Season the pizzas with a pinch of salt and black pepper, to taste.
Bake the flatbread pizzas in the preheated oven for 10-12 minutes, or until the cheese is melted and bubbly and the edges of the flatbread are golden brown.
Once cooked, remove the pizzas from the oven and let them cool for a minute. Garnish each pizza with torn fresh basil leaves. Drizzle a little extra-virgin olive oil over the top of each pizza. Optionally, sprinkle some crushed red pepper flakes over the pizzas for a touch of heat.
Slice the Margherita Flatbread Pizzas into wedges or squares and serve immediately.