Put the chicken, tomatoes, onions, zucchinis, dressing and chicken stock into your slow cooker.
Set the cooker on high and let cook for approximately 4 hours (or set to low and cook for 6-7 hours).
Fifteen minutes before dinner, heat oven to 375-400°.
Spread the shredded Asiago in a thin layer on a greased cookie sheet.
Bake until the cheese is brown but not burned, about 5 minutes.
Let the cheese cool for 2-3 minutes, then break into large pieces.
Serve the chicken with the cheese crisps on top and the stewed vegetables on the side.