Bring salted water to a boil. Parboil the broccoli for a minute and remove. Add the penne and cook for 8 to 10 minutes or until al dente.
In a large skillet heat the olive oil. When hot, add the onion and saute for 3 to 4 minutes. Add the chicken and saute, stirring continuously until no longer pink. Add the garlic and saute a few moments, then add the white wine, oregano and tomato sauce. Add the parboiled broccoli and simmer just to reheat. Season to taste with salt and pepper and garnish with Italian parsley. Drain penne and transfer to a bowl. Top with chicken and broccoli saute and serve.