Add onion, carrots and celery, and cook, stirring occasionally, about 5 minutes, until onions are tender.
Add stock, potatoes, bay leaf, thyme and chicken and cook until chicken is cooked through and carrots are tender, about 10 minutes.
Add cauliflower and cook for 5 more minutes.
Add dried noodles or pasta, zucchini, and kale, and cook until pasta is al dente (meaning that it still has some chewiness when you bite), 5-7 minutes, depending on the size and type of noodles.
Remove from heat and stir in frozen peas, parsley, salt & pepper, and red pepper flakes, if using. Remove bay leaf and serve hot.
Notes
If using cooked leftover chicken or turkey, add when the noodles are cooked.