1 tablespoon Olive Oil
1 medium Leek, white and pale-green parts only, halved lengthwise, sliced crosswise 1/2-inch thick
1 Celery Stalk, sliced crosswise 1/2-inch thick
12 ounces skinless Chicken Breasts
6 cups low-sodium Chicken Broth
1/2 cup Orzo
1/4 cup chopped fresh Dill
Kosher Salt, freshly Ground Pepper
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.