Lemon Chicken and Orzo Soup

1 Tbsp. olive oil
1 medium leek, white and pale-green parts only, halved lengthwise and sliced crossways ½” thick.
1 celery stalk, sliced crosswise 1/2″ thick
12 oz. skinless. Boneless chicken thighs
6 cups low-sodium chicken broth
kosher salt, freshly ground pepper
½ cup orzo
¼ cup chopped fresh dill
lemon halves (for serving)

Heat oil in a large heavy pot over medium heat. Add leek and celery and cook, stirring often, until vegetables are soft, 5-8 minutes. Add chicken and broth; season with salt and pepper. Bring to a boil, cover, reduce heat, and simmer until chicken is cooked through, 15-20 minutes. Transfer chicken to a plate. Let cool, then shred chicken into bite size pieces.

Meanwhile, return broth to a boil. Add orzo and cook until al dente, 8-10 minutes.

Remove pot from heat. Stir in chicken and dill. Serve with lemon halves for squeezing over.