Preheat your oven to 375 F (190°C).
To make cauliflower rice from scratch, cut a large head of cauliflower into smaller florets. Grate these florets using a box grater with medium-sized holes or use a grater attachment on your food processor. Alternatively, you can buy pre-riced cauliflower. Bring a large pot of water to a boil and add the riced cauliflower. Mix and cook for 5 minutes until the rice is soft.
Drain the cauliflower rice with a fine mesh strainer or a kitchen towel. Once most of the water has drained, set the rice aside to cool for 5 minutes.
While the cauliflower rice is cooling, mix the flaxseed meal and water and form it into a ball. Set aside.
Wrap the cooled cauliflower rice in the dish towel and ring out as much water as you can. You want to remove as much moisture as possible.
Add the cauliflower rice, prepared flaxseed ball, almond flour, oregano, onion powder, sea salt, and chopped basil leaves to a large mixing bowl.
Use your hands to combine the ingredients thoroughly.
Spread the dough on a baking sheet dusted with gluten-free flour and shape into a circle. It should be roughly 1/2 inch (1.5 cm) thick with slightly thicker edges.
Bake the crust for 30 minutes, then remove from the oven.
Add a thin layer of tomato sauce and your chosen toppings. Bake for another 10-15 minutes until the edges are golden brown and the base is cooked through.
While the pizza is in the oven, add all of the ingredients for the basil pesto into a food processor and process until they come together. If it isn’t mixing smoothly, add some water.
Remove the pizza from the oven, spread some of the freshly prepared basil pesto onto the pizza, and serve hot.