In a large bowl, mix together masa harina, hemp, flax and salt. Slowly pour in water a little at a time. You may not need all the water as it varies. Keep adding water until you can start form balls with the dough. Use your hands to knead the dough for 2 minutes until you have a smooth ball. Add water or flour as needed to get a soft and pliable dough. Cover with a damp cloth and let it rest for 10 minutes.
Divide dough into 14 equal sized dough balls, about 40 grams a piece. Roll the balls in the palm of your hands until they are smooth and round. Heat a skillet (non-stick or cast iron) over medium-high heat.
Place dough balls, one at a time, between two pieces of parchment (or reusable plastic*) in a tortilla press and flatten into a round tortilla. Gently peel the tortilla away from the parchment. If it sticks entirely, the dough it too soft and you'll need to add a bit more flour. Cook the tortilla for about 60 seconds per side. Bubbling up is a sign of a healthy dough. Transfer cooked tortilla to a tortilla warmer or a bowl wrapped in a clean tea towel, to keep them soft and most. Serve right away.
If eating later, warm tortillas in a closed container in the microwave or oven. Make sure they are well covered to prevent them from drying out.