If using frozen shrimp, place in cold water for 15-30 minutes until thawed. Drain and remove the shells if applicable. Pat shrimp dry with a paper towel to remove excess water. Season with old bay.
Allow a skillet to warm on the stove over medium high heat. Once warmed, add olive oil and 2 tbsps of butter and allow it to melt together.
Place shrimp in the skillet and cook for 2-3 minutes, then flip and continue to cook for another 1-2 minutes, until pink and slightly curled. (Tip: cook shrimp in batches to avoid overcrowding the pan) Add more butter to the pan as needed.
Once shrimp is finished cooking, remove the shrimp from the pan. Add remaining butter to the pan and add diced garlic and rosemary. Cook for 2-3 minutes, until fragrant.
Then add red pepper flakes, chicken broth, and parsley. Continue to cook for 5 minutes, stirring until a sauce forms. Squeeze 1-2 lemon wedges into the sauce.
Coat shrimp in the sauce and serve with lemon wedges.