To poach the chicken, place chicken, onion, lemon, carrot, celery, bay and herb bundle in a pot, cover chicken with water and bring to boil. Once boiling, reduce heat and simmer 45 minutes. Strain and reserve poaching liquids, cool chicken to handle. Remove skin and bones then pull meat into thin, bite-sized pieces.
For the pasta, heat EVOO, 1 turn of the pan, with butter over medium heat. Add carrots, zucchini, leeks and garlic, season with salt and white pepper, and sauté to tender, 6-7 minutes. Sprinkle veggies with flour and stir a minute more. Deglaze pan with wine then stir in 2 cups reserved poaching liquid. Thicken to lightly coat spoon, add in chicken and peas, and reduce heat to low.