Arrange green beans in a microwave-safe dish (I used a pie plate) with ½ cup water. Cook for 4 minutes, until just barely fork tender but still crisp (they will finish cooking in the skillet).
Meanwhile, in a small bowl, combine the Italian seasoning, onion powder, smoked paprika, ½ teaspoon salt, and pepper. Set aside.
Heat the oil and 1 tablespoon butter in a 12-inch skillet or sauté pan over MEDIUM heat. Add the chicken, spread it out into one layer, and increase the heat to MEDIUM-HIGH. Cook undisturbed for about 4 minutes then sprinkle the seasoning mix over the top and stir. Cook, stirring occasionally for another 5 to 6 minutes, or until cooked through. If the chicken browns too quickly, lower the heat. Remove the skillet from the heat, transfer the chicken to a plate, and set it aside.
In the same skillet, over MEDIUM-LOW heat melt the remaining 2 tablespoons butter. Add the partially cooked green beans, half of the parsley, garlic, remaining ½ teaspoon salt, and red pepper flakes, and cook for 2 to 3 minutes, stirring regularly. Add the lemon juice and chicken broth, increase the heat to MEDIUM-HIGH, and cook, stirring occasionally for 2 to 3 minutes to reduce the liquid a little.
Add the chicken back to the skillet and toss with the green beans and remaining parsley. Garnish with lemon slices.