Overstuffed Portobello Mushroom Bake

Hello, Zoners! I love delicious foods, but can only really enjoy them if they are healthy. Since I started the Zone program only one week and a half ago, I've been able to eliminate my morning coffee and following the program very closely am already noticing a big increase in my energy and mental focus. To date, I have lost 6 pounds. Below is one of my newest Zone creations. It is very filling, a full plateful, and is a 3-block meal. I hope you will all enjoy it as much as I do.

Ingredients:
1 large Portobello mushroom cap (stem removed and chopped for filling) (If Portobello is quite thick, cut out a bowl of mushroom "meat" and chop and add to mixture)
2 cups chopped white mushrooms
1 cup Vidalia onion, celery, red peppers, plenty of garlic (to taste) all chopped
1 Tomato, chopped
1/4 cup red lentils (already cooked and mashed)
1/4 cup skim mozzarella cheese, shredded
1/4 cup egg substitute (or 1 egg)
1 teaspoon olive oil

Instructions:
Preheat oven to 400 degrees.Spray large fry pan with non-stick spray. Add chopped onion, celery, peppers, and garlic. Cook till tender. While chopped veggies are cooking, put portobello cap into non-stick sprayed pan into the oven to start the cooking process.