1 tbsp. butter
¾ cup orzo pasta
3 tbsp. olive oil
1 onion, chopped
1 large leek, white and pale-green parts only—quartered lengthwise, then cut crosswise into 1/2-inch pieces
2 stalks celery with leafy tops, chopped
1 large carrot, peeled and chopped
2 tbsp. fresh thyme, chopped
3 cloves garlic, chopped
1 large bay leaf
1 lemon, zested (about 1 1/2 tsp.) and juiced (about 1/4 cup)
Salt and pepper
1 qt. chicken stock
1 small rotisserie chicken, meat pulled into small pieces and skin and bones discarded
In a small saucepan, melt the butter over medium heat. Add the orzo and cook, stirring often, until deep golden brown, 2 to 3 minutes.
In a large Dutch oven or soup pot with a lid, heat the oil, three turns of the pan, over medium-high. Add the onion, leek, celery, carrot, thyme, garlic, bay leaf, and lemon zest. Season with salt and pepper and cover the pot. Cook the vegetables, stirring occasionally, until softened, 7 to 8 minutes. Add the stock and 1 cup water. Bring to a boil over high heat. Add the orzo and chicken. Cook until the orzo is al dente and the chicken is heated through, about 7 minutes. Add the lemon juice; season with salt.