Over medium high heat in a skillet, brown the chorizo and remove from the pan, setting it on a paper towel lined plate.
Sauté the grated zucchini & chopped onion in the chorizo drippings until tender and slightly carmelized, about 7 mins
Return the chorizo to the pan and cook a few more mins to let the flavors combine.
Reduce heat to low and grated cheddar over the chorizo. Carefully crack your desired amount of eggs on top of the chorizo and cover with a lid to steam until yolk is cooked to your liking, I do about 3 mins for a jammy yolk
With a spatula, separate and scrape a section onto a tostada and top with avocados & desired toppings