Pot-Roasted Celery Root with Olives and Buttermilk

Ingredients

• 1 cup buttermilk 
• 6 small celery roots with some stem still attached trimmed unpeeled (celeriac; each 4 ounces)
• 1 tablespoon coffee-bean granita 
• 6 servings kosher salt 
• 0.5  optional: lemon 
• 0.3 cup oil-cured olives black pitted quartered
• 3 tablespoons olive oil extra-virgin plus more for drizzling
• 6 sprigs rosemary 
• 6 sprigs sage 
• 12 sprigs thyme leaves 
• 0.5 cup butter unsalted cut into 1" cubes (1 stick)

Equipment

• frying pan
• sauce pan
• pot

Directions

1. Heat 3 tablespoons oil in a large heavy pot overmedium heat.
2. Add celery roots and cook,turning frequently, until golden, 8-10minutes.
3. Add butter and a large pinch ofsalt. When butter begins to foam, reduceheat to medium-low.
4. Add herb sprigs,coffee beans, if using, and 1 1/2 cups water.Cover and gently cook, adding morewater by tablespoonfuls if pan is dry, untilcelery roots are very tender, about 1 hour.
5. Remove herbs and coffee beans (ifusing) from pot and discard. Baste celeryroots with buttery juices in pot.
6. Removefrom heat.
7. Transfer celery roots to a cuttingboard, slice in half through stems, andplace 2 halves on each plate.
8. Meanwhile, very gently warm buttermilkin a small saucepan over low heat (it willbreak if warmed too much). Squeeze in afew drops of lemon juice and add remaining2 teaspoons oil and a pinch of salt to make a loosesauce. Spoon sauce around celery rootson plates.
9. Garnish with olives, drizzle withoil, and squeeze a few more drops of lemon juice over each.