Cook the green beans according to package directions until tender but still a bit crisp. Set aside.
Season the chicken thighs on both sides with salt, pepper, onion powder, and paprika. Melt 1 ½ tablespoons of butter plus one teaspoon of olive oil in a large skillet and brown the chicken thighs on both sides over medium-high heat (about 5 minutes on each side until fully cooked). Transfer to a plate and set aside.
In the same skillet, melt ½ tablespoon of butter, and saute the garlic, chopped parsley, and Sriracha for about 30 seconds.
Pour in the chicken broth and lemon juice. Simmer until slightly thickened, about 2 minutes.
Add the green beans and cook for 2 minutes. Season with salt and pepper if needed.
Cut the chicken thighs into bite-size pieces (Cutting them after they’re cooked keeps them juicy). Push the green beans to one side of the skillet and place the chicken on the other. Serve with freshly chopped parsley and lemon slices on top.