what other cookoffs are there?

Not really sure what the workplace leniency is for cooking while working, so it sounds like you are stuck with a slow-cooker. That being said, I am looking at extra things made at a BBQ comp. Sides, sauce, and dessert. You could have a couple people bring meat, then others go for best sauce. Best sides to go with BBQ. Best beans? I have done a "soup" cookoff, but there were different kinds and it was very divided depending on peoples preferences of soup. You would want to try and keep it the same food. Otherwise, just plan a potluck and have fun?

Another employee and myself had a rib off. We both cooked on mini uds's. Timing works out well with Ribs but I am sure the pool of participants would be even smaller if you went that way.

I always wanted to do a stew cookoff.

Ive seen soup contests and bake off's. it seems that they want the employee interation as long as it doesnt take time away from the work day.

I won a company chowder cookoff

We have a soup party/cook-off every year at our boat club. Not really a contest, but there's always an unofficial fan favorite.

I started a biscuits and gravy cook-off at my previous job. Different people brought it on different days, so hard to compare. Made before work, so it fit with the slow cooker requirements.