Sauté Vegetables: Heat butter in a large stock pot over medium-high heat. Add diced celery and carrots, sautéing for about 3 minutes. Add minced garlic and cook for an additional 30 seconds.
Prepare the Broth: Pour in chicken stock and season with salt, pepper, and dried herbs (rosemary, sage, basil, oregano, parsley). Taste and adjust seasoning as needed. Add a spoonful of Better Than Bouillon or chicken bouillon granules for added depth of flavor.
Cook the Pasta: Bring the broth to a boil. Add chickpea orzo (or rice) and cook for the specified time on the package, minus 5 minutes.
Add Vegetables: During the final 5 minutes of pasta cooking time, stir in broccoli and cauliflower. Cook until the vegetables are just tender but still vibrant.
Add the Chicken: Stir in shredded rotisserie chicken and allow the soup to heat through. Taste the broth again and adjust seasonings, if needed.
Serve & Store: Serve immediately or store leftovers in an airtight container in the refrigerator for 4–5 days, depending on the freshness of the chicken.