Peel and finely dice your onion. Wash and finely dice your carrot and celery.
Get a large pot hot. Gloss with oil. Add your diced veg. Season well. Lower heat. Sizzle till nicely softened, about 7 mins.
Peel and finely chop the garlic. Strip the leaves from your thyme. Swirl the garlic and 2 tsp thyme leaves into the mix. Drain your beans. Add them. Fill the tin with water. Add it. Simmer for 5 mins.
Blend till smooth. Taste. Whizz in more thyme and add more salt and pepper to suit your palate.
Finish the soup with a scattering of the remaining thyme leaves.