In a large pot on a medium – high heat, bring the olive oil to heat. Add the onion, carrot, celery and garlic to the pot and sauté for 5 minutes or until fragrant and the onion is translucent. Stir often. Add the potatoes to the pot and cook for an additional 2 minutes.
Add the stock to the pot and bring to the boil. Once boiling, reduce the heat and simmer for 15 minutes. Bring back to the boil, add the pasta and cook for 3 minutes or until the pasta is plump and al dente.
Reduce the heat, add the peas, chicken and parsley to the pot and stir through. Squeeze over some lemon juice and season to taste. Serve immediately.