Bring a large pot of water to a boil for the pasta.
Heat a large skillet over medium to medium-high heat with EVOO, 1 turn of the pan. Melt butter into oil then add chicken and brown and crumble. Season chicken with salt, pepper and fresh herbs; add carrots, celery, leeks and garlic, and cook 7-10 minutes, stirring frequently. Add in tomato paste and cook for couple minutes. Add wine and reduce a minute; add stock and reduce heat to a low simmer. Add peas, if using, and let simmer sauce while the pasta cooks.