Silky Celery and Potato Soup

From the garden

• 8 stalks celery, sliced, leaves reserved · a whole bunch, and the leaves go in too
• 1 lb potatoes, peeled and cubed · the only thickener; a floury variety blends silkiest
• 1 large yellow onion, sliced
• 3 cloves garlic, sliced

From the pantry

• 4 tbsp olive oil · divided; some goes in the pot, some over the bowls
• 5 cups vegetable stock
• 1 bay leaf
• 1 lemon · juice only
• crusty bread (optional) · for serving
• salt · to taste
• black pepper

1. Warm 3 tablespoons of the olive oil in a soup pot over medium heat and sweat the sliced celery and onion with a good pinch of salt, about 10 minutes, until soft and sweet. Keep them pale: browning pushes the flavor toward stock.
2. Stir in the garlic for a minute, then add the potatoes, stock, and bay leaf. Simmer partly covered 20 to 25 minutes, until a knife slides through a cube of potato with no resistance at all.
3. Drop in the reserved celery leaves and simmer just 2 minutes more. They go in late on purpose, so the soup keeps the grassy top note that separates it from plain potato soup.
4. Fish out the bay leaf and blend until completely smooth, in batches or with an immersion blender. Blend longer than feels necessary; garden celery is stringy, and only a patient blend turns it silky. Push it through a sieve if you want it flawless.
5. Season with the lemon juice, salt, and plenty of black pepper, working up on the salt until the celery flavor lifts. Serve with the last of the olive oil threaded over each bowl and bread alongside.