In a large soup pot over medium heat, warm the olive oil and butter. Add the diced onion, celery and carrots, season with salt & pepper, and sauté until softened, 6-8 minutes. Add the minced garlic and stir for another minute
Add the broth and water and bring to boil. Once bubbling, add the chicken and spaghetti noodles. Season liberally with salt & pepper and reduce heat to medium. Simmer for 15-20 minutes, stirring occasionally. Once the noodles are cooked, you are ready to eat! Add the fresh herbs, if using, taste for seasonings and serve
You may need to add more broth if reheating for leftovers