Finely dice the garlic and onion. Pluck the leaves from the basil stems and set aside. Do not discard the stems, they will still be needed.
Sauté the garlic and onions in the oil and add the vegetable stock and cream, now add the basil stems and simmer for about 10 minutes.
Now remove the basil stems and add the crème légère and mix. Just before serving, add the chopped basil leaves. Serve with ravioli tossed in the sauce and garnished with basil.