Prep the beans. Trim the ends and cut the green beans in half.
Rinse and pat dry so they sear, not steam.
Brown the beef. Heat a large skillet over medium-high. Add 1 tablespoon oil, then the ground beef. Season lightly with salt and pepper.
Cook, breaking it up, until well browned with some crispy bits, about 6–8 minutes. Spoon off excess fat if needed.
Build flavor with aromatics. Push the beef to one side. Add the remaining oil, onion, and a pinch of salt to the empty space.
Sauté 2–3 minutes until softened, then stir in garlic for 30 seconds until fragrant. Mix back into the beef.
Toast the spices. Sprinkle in smoked paprika, cumin, onion powder, and red pepper flakes. Stir for 30–60 seconds to bloom the spices.
Add the beans. Toss in the green beans and stir to coat.
Let them sit undisturbed for 1–2 minutes to get a bit of char.
Make the quick sauce. Stir in tomato paste and soy sauce. Add the beef broth, scraping up any browned bits from the pan. Reduce heat to medium and let it simmer 4–6 minutes, until beans are crisp-tender and the liquid reduces slightly.
Finish with butter and acidity. Stir in butter until melted and glossy.
Taste and adjust salt and pepper. Add a small squeeze of lemon juice if you like a bright finish.
Garnish and serve. Top with chopped parsley or green onions. Serve hot straight from the skillet.