Start by bringing a large pot of salted water to a boil. Once bubbling vigorously, add the penne and cook until just al dente, about 9 minutes. Drain and set aside, reserving a cup of pasta water.
While the pasta cooks, peel and devein the shrimp, then pat them dry with paper towels. This helps them sear properly and prevents splattering.
Heat the olive oil in a large skillet over medium-high heat until shimmering. Add the minced garlic and cook for about 30 seconds until fragrant but not browned, filling your kitchen with a bright, pungent aroma.
Add the shrimp in a single layer and sear for 2 minutes without moving, until they start to turn pink and develop a slight golden edge. Flip them over and cook for another 1-2 minutes until fully pink and opaque. Remove the shrimp from the pan and set aside.
If the pan looks dry, add a splash more olive oil. Pour in the lemon juice and crushed red pepper flakes, stirring for about 30 seconds to meld the flavors and lift any browned bits from the bottom of the skillet.
Return the cooked shrimp to the skillet along with the drained penne pasta. Toss gently to coat the pasta and shrimp in the fragrant garlic oil mixture. If the mixture feels a bit dry, add a splash of the reserved pasta water to loosen and create a silky sauce.
Sprinkle the chopped parsley over the pasta, then toss again to evenly distribute. Let everything warm through for about a minute, allowing the flavors to meld beautifully.
Remove the skillet from heat and give the dish a final gentle toss. Check for seasoning—add more lemon juice or parsley if desired. Serve immediately, garnished with extra herbs and a drizzle of olive oil if you like.
