Blanch or steam the green beans: Add green beans to a skillet with 1/4 cup water and a pinch of salt. Cover and cook over medium heat for 3–4 minutes, until bright green and just tender. Drain any excess water and transfer beans to a plate.
Brown the turkey: In the same skillet, heat 1 tablespoon olive oil over medium-high.
Add ground turkey, breaking it up with a spatula. Season with 1/2 teaspoon salt and 1/4 teaspoon pepper. Cook 5–7 minutes until browned and mostly cooked through.
Push turkey to one side of the pan.
Sauté the aromatics: Reduce heat to medium. Add 1 tablespoon butter to the empty side of the skillet. Stir in onion and cook 2–3 minutes until softened.
Add garlic and cook 30–60 seconds until fragrant.
Season and combine: Sprinkle in the remaining salt and pepper, paprika, and red pepper flakes if using. Stir the turkey and aromatics together until evenly seasoned.
Make it saucy: Add soy sauce and lemon juice. Stir to coat.
Add the remaining 2 tablespoons butter and let it melt, creating a glossy garlic butter sauce that clings to the turkey.
Add the green beans back: Return green beans to the skillet. Toss everything together for 1–2 minutes. If the pan looks dry, splash in a tablespoon of broth to loosen.
Taste and adjust with more salt, pepper, or lemon.
Finish and serve: Remove from heat. Stir in chopped parsley. Serve hot as-is or over rice, quinoa, or cauliflower rice.
Add lemon wedges on the side if you like brightness.