This recipe was adapted from a ceviche recipe I have prepared in the past, except that I decided to use the blended sauce as a marinade for a short time instead of letting the lime juice cook the shrimp for several hours. And instead of discarding the marinade, I cook it down with sauteed onions and serrano pepper. The flavor of the grilled shrimp combined with the sauce is the perfect topping for crunchy corn tostadas or homemade chips. If you have not broken out the grill in while, the shrimp can be stir-fried on the stove top at high heat as well. Whichever way you decide to prepare this shrimp recipe, make sure you do it soon. Pick up some extra chips for that salsa because you won't be able to stop eating it!
In the blender, combine the half of the diced onion, 2 cloves garlic, half of the serrano peppers, poblano, tomatillos, 1/3 cup cilantro, lime juice, 3 tablespoons olive oil, pepper, cumin, oregano and salt to taste. Blend on high until smooth, taste for salt. Pour over cleaned shrimp, cover and chill for 1 hour.
For the Salsa: Combine the tomatillos, onion and serrano peppers in a pot. Cover with water, bring to a boil, reduce heat and cook for 10 to 15 minutes. Drain the water and let cool for 30 minutes. Transfer to the blender, add all remaining ingredients for salsa. Blend on high until smooth, taste for salt.
Remove shrimp from refrigerator, drain shrimp and reserve the marinade. Using metal or wooden skewers, add 5 to 6 shrimp per skewer, set aside. I like using the skewers because it much easier to turn the shrimp when grilling, but you can lay them directly onto grill.
In a sauce pan, preheat 1 tablespoon of olive oil to medium heat. Add the reserved onions and chile peppers and cook for 5 minutes. Add the reserved marinade from shrimp. Bring to a boil, reduce to simmer and cook for 15 to 20 minutes. Cover and remove from heat.
Preheat a stove top grill pan or outdoor grill to medium heat. Drizzle shrimp skewers with olive oil or spray with oil. Grill the shrimp for just 2 to 3 minutes per side or until it turns pink. Remove shrimp from skewers. Roughly chop 3/4 of the shrimp and toss with warm marinade sauce, reserving at least 8 whole shrimp. To plate, add some guacamole salsa to a tostada, top with shrimp in sauce, a whole grilled shrimp, cilantro, lime and crushed red pepper.