Mix together the water and ground flax seeds and set it aside to gel together for about 10 minutes.
If you are using frozen riced cauliflower, thaw it until it comes up to room temperature. If you are using freshly grated/processed cauliflower, microwave or steam it for 6 minutes and then let it cool down to room temperature.
Once the cauliflower is at room temperature, transfer it into either a nut milk bag or a cheesecloth and squeeze out ALL the water. It is VERY crucial that you squeeze out all the water otherwise the crust will fall apart. After squeezing a few times, move the cauliflower around and keep squeezing until there is no more water left in it.
Reserve the cauliflower water for soups/curries/stews or as fertilizer for your plants and transfer the completely dried out cauliflower into a large bowl.
Preheat your oven to 375F/190C.
Add in the gelled flax mixture and all the other ingredients under the crust section into the same large bowl and first mix together with a spatula and then with your hands. Mix only until the mixture comes together and a rough dough ball is formed.
Line a large baking sheet with parchment paper and transfer the dough ball onto the parchment paper. Pat down the dough with your hands until you form a circle roughly around 12" in diameter. Try to keep the center thinner than the sides and use your hands to shape the sides so you have a crack-free uniform edge.
Bake in the preheated oven for around 2-25 minutes or until the top is lightly golden brown around the edges.
Carefully take the pan out of the oven and use the parchment paper to help you flip the pizza crust onto the pan. Now peel off the parchment paper and bake for another 15 minutes.