A chicken and orzo soup that’s fresh enough for spring, with leeks, peas and asparagus

Once the chicken is removed from the broth, increase the heat to medium-high and add the carrot, celery, leeks, thyme, red pepper flakes (if using) and the remaining salt and cook until the vegetables have softened, about 10 minutes. Add the chicken, orzo, asparagus and peas and cook until the orzo is tender and the asparagus is crisp-tender, about 7 minutes, stirring two or three times to prevent the orzo from sticking to the bottom of the pot.