In a large pot of boiling salted water, cook the linguine or spaghetti according to package instructions until al dente. Reserve about ½ cup of pasta water, then drain the pasta.
Preheat your oven to 375°F (190°C). In a mixing bowl, combine softened butter, minced garlic, chopped parsley, and salt. Cut the French bread in half lengthwise and spread the garlic butter mixture evenly over each half. Place on a baking sheet and bake for about 10 minutes, or until golden and crispy.
In a large skillet, heat olive oil and butter over medium heat. Add the minced garlic and red pepper flakes. Sauté for about 1 minute, making sure not to burn the garlic.
Add the shrimp to the skillet and cook for 2-3 minutes on each side, or until they turn pink and opaque.
Pour in the white wine (or chicken broth) and lemon juice. Cook for an additional 2-3 minutes, allowing the sauce to reduce slightly. Season with salt and pepper to taste.
Add the cooked pasta to the skillet, tossing to combine with the shrimp and sauce. If needed, add reserved pasta water a little at a time to reach desired consistency.
Remove the skillet from heat and stir in chopped parsley. Divide the shrimp scampi mixture into bowls and serve with slices of garlic bread on the side.