Drain the beef, reserving the marinade. In a large skillet on high heat, heat 2 tbsp oil. Add beef and sear for 2-3 min on each side. Add in the peppers, onions, and tomatoes. Saute for 2-3 minutes. Add in 3-4 tbsp of the reserved marinade and boil for 2-3 minutes or until sauce thickens. Toss in the parsnips fries and season with salt, cilantro, and green onions.