What are good beef stew vegetables besides carrots, potatoes, celery, mushrooms, and onions?

Try sweet potatoes, leeks, parsnips, golden beets, and any other vegetables at the grocery store that look like they’d match one of the pre-existing ones you use.

Parsnips are very good.
If you decide to add peas add them during the final bit of cooking or they get all mushy and sort of gray green.
Try using some sweet potatoes rather than white potatoes.
The little baby red potatoes are good also.

Any root vegetable will work: rutabaga, parsnips, turnips, yams, sweet potatoes, daikon. Also winter squash would work too. I wouldn’t use peas (as suggested above) or anything else that will cook too quickly and get mushy in there.

Garbanzo beans(chick peas), red and green peppers, sweet potatoes