Cook the pasta according to the directions on the package.
Meanwhile, in another large, heavy-bottomed pan, melt the butter and olive oil over medium-low heat.
Add the garlic and sauté for 1 minute. (Keep a close eye on it because the garlic can burn easily)
Add the shrimp, sea salt, and the pepper. Sauté until the shrimp have just turned pink, stirring often (~ 5 min).
Remove from the heat, add the parsley, lemon zest, lemon juice, lemon slices, and red pepper flakes. Toss to combine.
When the pasta is done, drain the cooked linguine and then put it back in the pot. Immediately add the shrimp and sauce, toss well, and serve.