-Thaw shrimp and rinse. Remove tails (optional) and keep cool until ready to cook.
-Heat olive oil and butter in a large sauté pan on medium heat.
-Add minced onion and garlic. Cook for approximately 5 minutes. Add the red pepper flakes and cook for a few minutes.
-Meanwhile, in a large stockpot, cook the pasta following the package directions and drain.
-Add the jarred salsa to the pasta and stir to combine thoroughly. Cover and keep warm.
-Returning to the sauté pan, add the lemon juice (remember to zest it first) to the garlic, onions, and red pepper flakes, and then add the shrimp.
-Cook only a few short moments on medium/low heat until the shrimp curl up a bit and turn opaque (if they're uncooked, to begin with). Do not overcook.
Notes
Store any leftovers in an airtight container in the refrigerator for up to 5 days.