I think ummmm's suggestion is good.
If all the veg and chicken had been previously cooked, I would have suggested cold chicken and Bungy( My name for reheated veg into which anything you like is simply 'bunged')
Chop onion and place in a microwavable dish with a tablespoonfull of oil and heat on full power for 4mins. I sometimes add a good handful of frozen sweetcorn and/or peas. Whilst the onion etc is cooking, roughly chop all other previously cooked veg( Carrots,pots. broccoli etc.) then mix together with the cooked onion, along with a teaspoonful of mixed herbs and a tablespoonful of mayonaisse or salad cream, together with a few good twists of ground pepper. Reheat the prepared 'bungy' in micro for five mins and serve. ...Sounds a real mess,but it's easy to do, tastes good and both Viv and I enjoy it.( With of course a few glasses of our red plonk)
Ron.