Heat the olive oil in a large pot over medium-heat. Add the onion, carrots, celery and garlic; sauté 5 minutes. Sprinkle the flour, oregano, thyme and poultry seasoning over the vegetables, and cook 1 minute. Stir in the broth and salt. Bring to a boil; reduce heat, and simmer, partially covered, for 25 minutes.
Add the roasted chicken, evaporated milk and noodles, and cook 10 minutes or until the noodles are tender. Stir in the frozen peas. Heat until the peas are warmed, and serve. Garnish with fresh thyme, if desired.