Make chimichurri sauce first. Add fresh parsley, garlic cloves, and shallots to a food processor. Pulse for about 5-10 seconds, until the ingredients are still chunky but all diced. Add to a medium bowl, then pour in the extra virgin olive oil, red wine vinegar, lemon juice, oregano, cumin, red pepper flakes, kosher salt, black pepper, and red pepper flakes. Mix together and set aside.
(If needed, peel and devein shrimp) Pat shrimp dry and place into a separate bowl. Season with smoked paprika, onion powder, celery salt, and a packet of sazon.
Drizzle olive oil into a cast over medium heat. Let the pan warm for 3-5 minutes, until hot, then add shrimp and cook on each side for 2-3 minutes, until pink and slightly curled. Remove from heat and toss shrimp in about 1/4 cup of the chimichurri and mix together.
Sprinkle parmesan and additional red pepper flakes on top. Serve with the remaining sauce on the side.
Notes
I like to use the food processor to make the chimichurri as opposed to chopping everything up - however, if you don't have one or want to avoid the extra dishes, you can just diced the parsley, garlic, and shallots by hand. Fresh ingredients are key! This is how you get that robust flavor - the fresh herbs, fresh garlic, etc. all shape this dish and provide the most delicious bite.Don't overcrowd the pan when cooking the shrimp. You want a good sear and the major key to that is cooking them in a single layer and spacing them apart.