Prep the shrimp. Pat the shrimp dry with paper towels so they sear instead of steam. Season with salt, pepper, and smoked paprika if using. Set aside while you prep the beans.

Blanch the green beans. Bring a medium pot of salted water to a boil. Add green beans and cook for 3–4 minutes until crisp-tender and bright green. Drain and rinse under cold water to stop the cooking. Pat dry.

Sauté the beans. In a large skillet over medium heat, add 1 tablespoon olive oil and 1 tablespoon butter. When the butter foams, add the green beans. Season with a pinch of salt and pepper. Cook 3–4 minutes, tossing, until lightly blistered and glossy. Transfer to a plate and keep warm.

Sear the shrimp. In the same skillet, add 1 tablespoon olive oil. Increase heat to medium-high. Add shrimp in a single layer and cook 1–2 minutes per side until pink and just opaque. Do this in batches if needed to avoid crowding. Transfer shrimp to a plate.

Make the garlic butter. Lower the heat to medium. Add remaining 2 tablespoons butter to the skillet. Stir in the minced garlic and red pepper flakes. Cook 30–45 seconds until fragrant, not browned.

Deglaze and brighten. Zest half the lemon into the pan, then squeeze in 1–2 tablespoons lemon juice. Stir, scraping up any browned bits. Taste and adjust salt and pepper.

Combine. Return the shrimp and green beans to the skillet. Toss to coat in the garlic butter. Warm through for 1 minute. Sprinkle with chopped parsley and an extra squeeze of lemon if you like.

Serve. Plate as is, or spoon over rice, pasta, or with crusty bread to soak up the sauce. Serve immediately.