Preheat your oven to 450°F (232°C).

In a clean kitchen towel, combine the shredded zucchini and ⅛ tsp salt. Let it rest for 10 minutes.

Wrap the towel around the zucchini and squeeze out as much liquid as possible over the sink.

In a mixing bowl, combine the squeezed zucchini, the remaining ¼ tsp salt, masa harina, cheddar cheese, parmesan, garlic powder, cumin, and the egg. Stir until everything is well blended.

Divide the zucchini mixture into 6 equal portions, about ⅓ cup each. Press each portion into a 5-6 inch circle on a parchment-lined baking sheet.

Bake in the preheated oven for 20-22 minutes or until the edges are nicely browned.

Once cool enough to handle, carefully remove the shells from the parchment paper and fill them with your favorite taco fillings.