Wash and drain peas. In a large pot over medium heat add olive oil and onion and saute until onion is translucent.

Add parsnip, garlic, celery, and carrots. Sauté until vegetables begin to soften, about 4 minutes.

Add peas and vegetable stock plus enough water to cover all veggies, and bring to a boil.

Once boiling, reduce heat to low and simmer uncovered for about an hour or until vegetables are tender peas are falling apart, stirring often. Add salt and pepper to taste.