Have three plates or pie pans ready for the coating. 

If you are using fish that is frozen make sure you defrost it for several hours or overnight in the fridge. Make the spicy tartar sauce a couple of hours before or overnight to give the flavors some time to blend.

In the first plate mix the flour with the salt, pepper, and oregano. 

Crack the egg onto the second plate and beat well.

Place the breadcrumbs into the third plate. 

Pat the fish well, to dry from excess moisture, with paper towels and have them ready for coating. 

If you can, heat the tortillas either by briefly cooking on a skillet or in the oven for just a few minutes and then keep covered with a towel to keep warm. 

In a medium-sized pot, such as a dutch oven or straight-sided pan, Heat 3 inches of the oil to 375°. 

While the oil is heating, coat the fish pieces starting with the flour mixture, then the egg, and finally the breadcrumbs making sure at each step the fish is completely covered. 

Place the coated fish on a tray ready to fry. 

Have several layers of paper towels on a different tray ready for draining the cooked fish. 

When the oil reaches 375° fry the fish in several batches as to not crowd the pan and lower the temperature too far. 

Fry for 2 minutes until golden brown.

Let the oil come back up to 375° between batches. 

Drain the crispy fish on paper towels. 

Serve while still hot with tortillas, pieces of lettuce or cabbage, lots of the spicy tartar sauce and some lime wedges.