Making anything vegetarian/vegan is doable most of the time. I personally have never made one, but am very intrigued.
There are plant-based sausages and meat (check out Beyond Meat, it's chick'n, btw). I'm not sure if you wanted to make more of a completely vegetable jamabalaya or if you wanted to include those. Vegan Jambalaya
This recipe calls for Tempeh which is good stuff. You can get it at WF and season it to taste however you want. It's got a thick bite to it and can stand it's ground as the meat replacement. Vegetarian Jambalaya
I may try to make one of these soon. I know they had a "World Peace" something or other a couple weekends downtown and they were serving veg jam.