Ingredients
3 tablespoons olive oil
1 large onion, peeled, half coarsely chopped, the other half kept whole
2 large celery stalks, sliced 1/2-inch thick
2 medium carrots, unpeeled and sliced 1/2-inch thick
2 garlic cloves, thinly sliced
1/4 teaspoon whole black peppercorns
8 sprigs flat-leaf parsley
8 sprigs basil
4 sprigs thyme
2 dried bay leaves
Salt and pepper
Preparation
Heat the oil in a medium stockpot over medium until hot but not smoking. Add chopped onion and cook, stirring often, until beginning to brown, 10 to 15 minutes. Add celery, carrots, garlic, and peppercorns; cook, stirring occasionally, until vegetables are tender and lightly browned, about 10 minutes.
Pour in enough water to cover vegetables by 1 inch (8 to 10 cups) and add herbs and remaining half onion. Season with salt and pepper and bring to a boil. Reduce heat to a gentle simmer and cook, uncovered, 1 hour.
Pour stock through a fine sieve into a large bowl or another pot, pressing on vegetables to extract as much flavorful liquid as possible. Discard solids. If not using immediately, cool in an ice-water bath before transferring to airtight containers.
