In a pie plate or shallow dish, combine 1/2 cup flour, 1/2 tsp salt and 1/4 tsp black pepper. Stir with a fork to blend. Using tongs, coat the chicken breasts in the flour mixture, shaking off the excess. Add oil to a large skillet over medium-high heat. Place chicken in the skillet and cook until golden brown on both sides and cooked through, turning once between cooking, about 8-10 minutes. Remove chicken from pan and set aside. Add 4 Tbsp butter, onion and garlic to pan. Cook until onions are translucent, about 2 minutes. Add 1/4 cup remaining flour to pan and whisk to combine. Add cream, lemon juice, wine, red pepper flakes, salt, pepper and parmesan cheese. Whisk until is you have a smooth mixture. Add up to 1 cup of pasta water to help create the sauce. Add cooked pasta, half of scallions and half of tomatoes, stir to combine. Return chicken to skillet and allow it to warm. Sprinkle remaining scallions and tomatoes on top of skillet. Serve and enjoy.