Heat the olive oil in a large skillet over medium heat.
Add the minced garlic and sauté for about 1 minute until fragrant, making sure not to burn it.
If using, sprinkle in the red pepper flakes for added heat and cook for another 30 seconds.
Add the shrimp to the skillet, season with salt and black pepper, and cook for 2-3 minutes until they turn pink and are opaque, flipping them halfway through.
Pour in the chicken broth (or white wine) and lemon juice; stir to combine.
Sprinkle the grated Parmesan cheese over the shrimp, stirring gently to coat the shrimp evenly. Cook for an additional 1-2 minutes to allow the cheese to melt slightly.
Remove from heat, taste, and adjust seasoning if necessary.
Garnish with fresh parsley before serving.