If using polenta from a tube, skip to step 2. For instant polenta, bring 3 cups salted water to a simmer in a pot on medium heat. Slowly add the instant polenta, constantly stirring to ensure that clumps do not form. Continue stirring for 4 to 5 minutes until the polenta becomes very thick. Lightly grease a baking sheet and pour the polenta evenly into the pan so that it is approximately half an inch thick. Place the pan in the fridge for 45 minutes until it is hard. Once hard, remove form the fridge and cut into circles using a knife or cookie cutter.
If using a tube of polenta, cut 1/2 inch thick slices.
In a pot on medium low heat cook the crushed garlic in 1 tablespoon of olive oil until it begins to turn golden in color. Lower the heat, add the chopped onions, zucchini, mushrooms and eggplant, sprinkle with salt and cook for 10 minutes until the vegetables have become translucent in color. Add in the cherry tomatoes and continue to cook for another 5 minutes.
Add the honey, tomato paste and chopped tomatoes to the pot and allow the sauce to simmer for 10 minutes.
Heat the grill or barbecue. Lightly brush the polenta with olive oil and grill for 5 minutes per side or until they begin to turn golden in color and the edges become crisp.
Serve each circle of polenta topped with tomato sauce, chopped basil and Parmesan if desired.