Take the chicken breast off the roast chicken and put the chicken bones, wings and any other bits in a large microwave dish with the water and thyme. Cover and cook on high for 10 minutes.
While that is cooking, start on the prep of the veg.
Finely chop the onion and fry in the oil. Add a little salt to help season the veg as they are cooking.
Cut the celery into strips lengthways and then chop into small cubes. Add to the onion.
Peel and cube the carrot to about the same size as the celery. Add to the pot.
Add crushed garlic.
By this time the stock should be finished - unless you are particularly fast at veg prep!
Strain the stock over the vegetables.
Add the pasta shells or whatever pasta you happen to have.
Slice the chicken breast and pick off any good bits of chicken from the drained bones. Add to the pot.
Simmer for as long as it takes to cook the pasta – 13 minutes for my pasta shells.
Season to taste with salt and pepper.
Add more water if necessary. I needed to add a little more water after about 10 minutes.
Add the zucchini/courgette in the last 5 minutes of cooking. Slice the zucchini lengthways. Cut into triangular pieces. I find cutting the zucchini this way helps keep them in one piece in a soup where they may get overcooked when the soup is reheated.