In a soup pot, heat oil, two turns of the pan, over medium-high. Add the onion, celery, peppers and garlic; season with salt and pepper. Cook, stirring occasionally, until softened, 7-8 minutes.

Stir in the stock, tomatoes and the parmesan rind, if using. Bring to a boil. Add the green beans and pasta; cook at a low rolling boil until the noodles are al dente and the beans are crisp-tender, about 5 minutes.

Remove from the heat, add the chicken and stir until warmed through, about 3 minutes. Discard the Parmesan rind and stir in the basil. (For a brothier soup, add a couple of cups of water with the chicken stock.)