Finely chop parsley and oregano and set aside in a small bowl. Mince garlic and add to the bowl.
Add chili flakes, sea salt, olive oil, and vinegar and stir to combine.
I recommend storing in an airtight container for a few hours to allow the flavors to combine.
In a large bowl, toss shrimp with lemon juice, sea salt, and pepper.
If grilling – Skewer shrimp on bamboo skewers. Spray the grill with olive oil to prevent sticking. Over high heat, grill shrimp 1 minute per side.
If sautéing – heat 2 tablespoons of olive oil in a cast iron or nonstick skillet to medium high heat. Sear shrimp for 2 minutes per side.
Remove shrimp from heat (grill or skillet) and spoon chimichurri over top.