Cook the nopales with water, a tablespoon of salt, ¼ onion, and a clove of garlic. Let cook until softened. Separate.
While the nopalitos are cooking, clean the chiles, devein and remove the seeds.
Cook the ancho and guajillo chiles with water and a clove of garlic just until they boil and leave them to soak for about five minutes in the same water. Separate.
Blend the tomatoes with chiles and a little of the water where they were cooked.
Then you can strain the chile mixture to remove the skins (optional).
To form the patties:
Separate the egg whites from the yolks.
Beat the egg whites until stiff (like foam) and add the yolks one by one, continue beating.
Gradually add the ground shrimp and mix gently with a spatula, so as not to lose the stiff consistency.
Heat oil in a pan, enough, but do not cover the patties.
To form the patties, take a tablespoon of the shrimp and egg mixture and carefully place it in the pan.
You can fry several patties at the same time, you can usually fit three to four of them in the pan.
Flip them when you see they are browning, once, and let them brown on the other side.
Separate them and place them on top of a napkin to absorb the oil a little.
Incorporate shrimp patties and red sauce
Once you have all the patties ready, heat oil in a pan and fry half an onion in slices.
Add the chile mixture, plus three cups of water, season to taste with salt, and bring to a boil.
Stir in the nopales and patties carefully, shimmer for ten more minutes so that the flavors mix.