Salsa Macha

Recipe from: Alejandro Vazquez del Mercado 

1/3 Good cooking oil, not olive oil
1/3 Fresh Jalapeño peppers, without seeds, sliced long wise
1/3 White onion sliced
     Salt at your taste
 
Fry the onion until translucent, fry the Jalapeño peppers during 10 minutes, wait a little until they are cold, put the fried Jalapeño peppers and the onion (with the frying oil) in a blender, then start to add the remaining oil, slowly (a little stream), until the "Salsa" is done, it seems like a green mayonnaise.