Finely grate cauliflower and onion using grater or food processor. Combine in a separate bowl and add 1 teaspoon of sea salt flakes (to help draw out water) set aside for about 10 minutes.
Meanwhile, finely chop jalapeño and parsley and mince garlic. From there, squeeze the water out of the cauliflower and onion. I usually ring it out by squeezing a handful at a time and transferring it to a new bowl.
Add in the jalapeño, parsley, garlic, eggs, breadcrumbs, all purpose flour, baking powder, and remaining sea salt flakes to new bowl with cauliflower and onion. Mix thoroughly until all the ingredients are fully incorporated.
Preheat cast iron skillet over high heat.
Portion hash browns and form patties. I like using my ¼ measuring cup, so they are all equally portioned.
Add oil to your skillet to fully coat it (I like using canola, but any cooking oil should work nicely!). Add hash browns and cook until golden brown and crispy on both sides.