Place the cazuela over a medium flame. Add the olive oil. When hot (steam comes off the surface, do not burn the oil, you will know because it will smell rancid) add the garlic. Sizzle until golden in color, about 1 to 2 minutes. Add the chiles and leave for 1 minute.
Turn off the heat just as the garlic starts to turn brown. (If the garlic turns brown you have over cooked it and will need to start again.)
Add the shelled shrimps and leave for 2 minutes. Add a pinch of salt.
Serve with some fresh bread.