Prep the vegetables and chicken: dice the onion, celery, and carrots; shred or dice the roasted chicken; measure the orzo and broth.

Heat a large pot or Dutch oven over medium heat. Add 1–2 tablespoons of olive oil.

Add the diced onion, celery, and carrots. Cook, stirring occasionally, until softened and translucent, about 6–8 minutes. Season lightly with salt and pepper.

Pour in the 6 cups chicken broth and bring to a gentle simmer. Scrape any browned bits from the bottom of the pot.

Add 1 cup orzo and simmer, stirring occasionally, until the orzo is al dente—about 8–10 minutes depending on brand. Watch carefully so the orzo doesn’t overcook.

Stir in the 2 cups diced roasted chicken just long enough to heat through, 2–3 minutes.

Remove pot from heat and stir in 2 cups fresh spinach until wilted.

Add 1/4 cup lemon juice, taste, and adjust with more lemon, salt, or pepper as needed. Serve hot.