1 cup quinoa

1/2 small white onion, finely chopped

1 celery rib, cut into 1/4-inch dice

1 carrot, cut into 1/4-inch dice

1 small fennel bulb, trimmed, cored, and cut into 1/4-inch dice

1 tablespoon unsalted butter

1 1/2 cups vegetable stock

1 tsp salt or more to taste

Rinse quinoa in a bowl in at least 5 changes of water, rubbing grains and letting them settle before pouring off water, until water runs clear. Drain in a fine sieve.

Cook onion, celery, carrot, and fennel in butter in a 3-quart heavy saucepan over moderate heat, stirring occasionally, until onion is softened, 5 to 6 minutes. Add quinoa and sauté over moderately high heat, stirring, until lightly toasted, 2 to 3 minutes. Add stock and salt and pepper to taste and cook over moderately low heat, covered, until quinoa is tender and liquid is absorbed, 12 to 15 minutes.