1. Preheat the oven to 350 degrees F. Steam the fresh squash until very tender on top of the stove for aobut 10 minutes in 1/4 cup of water, or in the microwave, and drain.
2. Mash or puree the squash in a food processor, and in a large skillet saute the bell pepper and onion in the oil until tender. Mix the pureed squash, onion mixture, corn, sweetener and cornmeal, and add the salt and pepper (if desired).
3. Place the mixture in a 2-quart casserole dish coated with nonstick cooking spray, and bake for 30 minutes, or until it is bubbly and thoroughly heated, and serve.