Prep the shrimp: Pat shrimp dry with paper towels.
This helps them sear instead of steam. Season both sides with salt, pepper, and paprika if using.
Preheat the pan: Heat a large skillet over medium-high. Add olive oil and 1 tablespoon of butter.
When the butter foams, the pan is ready.
Sear the shrimp: Add shrimp in a single layer. Cook 1–2 minutes per side until just pink and slightly curled. Don’t crowd the pan; work in batches if needed.
Transfer to a plate.
Build the sauce: Reduce heat to medium-low. Add remaining 3 tablespoons butter to the skillet. Stir in garlic and red pepper flakes.
Cook 30–45 seconds until fragrant. Don’t brown the garlic.
Brighten it up: Add lemon zest and 1–2 tablespoons lemon juice. If you want more sauce, splash in 2–3 tablespoons stock and simmer for 30 seconds.
Finish the dish: Return shrimp and any juices to the skillet.
Toss to coat for 30–60 seconds, just until heated through. Sprinkle with parsley. Taste and adjust salt, pepper, and lemon.
Serve right away: Plate over warm zucchini noodles, cauliflower rice, sautéed spinach, or a crisp salad.
Spoon extra sauce over the top.