In a medium-sized bowl, combine the peeled and deveined medium shrimp with olive oil, lemon juice, minced garlic, paprika, red pepper flakes, and salt and pepper. Toss to coat well and marinate for 10 minutes.

In a large skillet, melt butter and remaining olive oil over medium-high heat. Wait for the butter to foam and become bubbly.

Add the marinated shrimp and lemon slices to the pan in a single layer. Sear for 2-3 minutes on each side until shrimp are opaque and slightly browning.

Turn off heat and sprinkle fresh parsley over the shrimp. Serve immediately over pasta or rice.