Turn the oven ideally as high as it will go, making sure two shelves are in place - about 240C/220C Fan/Gas 8. Spray a bit of oil on two large baking trays and put two tortillas on each.
Spray a little more on top of the gluten free tortillas and then rub the garlic infused oil all over the tortillas - this gives the pizza extra flavour.
Divide the chopped tomatoes evenly between the 4 gluten free tortillas, spreading them out but leaving a 1.5cm/¾in border. Scatter over the chili flakes, if using, and divide the cheese and peppers evenly over the top.
Pop both trays into the oven to bake for about 4-6 minutes (depending on how hot your oven is), or until the cheese has melted and the gluten free tortillas are crisp and golden-brown on their edges. Swap the trays around on the shelves half way through for even cooking.
Remove the gluten free tortillas from the oven and slide onto serving plates. Top with the low FODMAP pesto. Season with a little scattering of salt and pepper and serve.