Prep Work: Chop carrots and broccoli if using fresh; store together. Shred cheese if needed.
Heat butter in large skillet until bubbling. Add salt and flour with whisk. (Will be lumpy.) Preheat oven to 375 degrees.
Add broth 1/2 c. at a time, whisking continually to eliminate lumps. Add lemon juice and nutritional yeast and leave to simmer while preparing vegetables and chicken.
Cut carrots thin and place in 13 x 9 pan along with broccoli. Cut chicken into 1" square pieces and top vegetables.
Pour gravy over chicken and top with foil. Bake 35 min. Take out of oven and cut one piece of chicken to check for doneness. If no longer pink, top with cheese and bread crumbs return to oven uncovered for 10 more min. or until cheese melts. Serve with a plate of fresh cut vegetables with a quick dip.
*Nutritional yeast is not a living culture. It is grown on molasses and is loaded with extra B vitamins and amino acids; a very simple way to add a mega dose of natural vitamins to your diet. It also has a very slight nutty flavor which blends well with gravies, broth and meat. It can be purchased at a health food grocery store like Henry's Marketplace. Just ask for help the first time you go to look for it.