In a medium bowl, pat the shrimp dry with paper towels. Toss with 1 tbsp olive oil, minced garlic (from the 'For the Lemon Garlic Parmesan Shrimp' section), lemon zest, oregano, red pepper flakes (if using), 1/4 cup Parmesan cheese, and 1/4 cup chopped parsley. Season generously with salt and black pepper. Set aside.

Bring a large pot of heavily salted water to a rolling boil. Add the linguine and cook according to package directions until al dente. Reserve 1 cup of pasta water before draining.

While the pasta cooks, heat the remaining 1 tbsp olive oil (from the 'For the Lemon Garlic Parmesan Shrimp' section) in a large skillet over medium-high heat. Add the seasoned shrimp in a single layer, ensuring not to overcrowd the pan. Cook for 1-2 minutes per side, until pink and opaque. Remove shrimp from the skillet and set aside.

In the same skillet (do not clean it, the browned bits add flavor), melt the butter and add 2 tbsp olive oil (from the 'For the Lemon Butter Sauce' section) over medium heat. Add the 3 cloves minced garlic (from the 'For the Lemon Butter Sauce' section) and sauté for 30 seconds until fragrant.

Pour in the white wine (if using) or chicken broth and lemon juice. Bring to a simmer, scraping any browned bits from the bottom of the pan. Let it reduce slightly for 2-3 minutes.

Stir in the chicken broth and the remaining 1/4 cup of Parmesan cheese (from the 'For the Lemon Butter Sauce' section). Whisk until smooth and slightly thickened. Season with salt and pepper to taste.

Add the cooked and drained pasta to the skillet with the sauce. Toss to coat evenly. If the sauce seems too thick, add a little reserved pasta water, a tablespoon at a time, until it reaches your desired consistency.

Return the cooked shrimp to the skillet. Add the remaining 1/4 cup fresh parsley (from the 'For the Lemon Butter Sauce' section). Gently toss everything together.

Serve immediately, garnished with extra fresh parsley and Parmesan cheese, if desired.