Mix the tomato topping mixture together first because you will need a tablespoon to mix into the lentil loaf. The rest will be set aside to coat the loaf when completed.
Spray medium skillet with non-stick spray, cook chopped onions on medium heat until transparent (about 5 minutes), stirring frequently.
In a food processor chop oats for 5 quick pulses.
In a large mixing bowl combine oats, Griller crumbles, cooked onions, 1 tablespoon of tomato mixture, corn meal, lentils, balsamic vinegar, soy sauce, 1 tablespoon olive oil, thyme, cumin, chili powder, parsley, celery salt, sugar, garlic and onion salt, dried mustard and mix until well combined.
Spray a large sheet of tin foil with cooking spray to form loaf on, place on cookie sheet. On top and in the middle of tin foil form loaf mixture into loaf that is 2 1/2 inches tall and 4 1/2 inches square. Coat top and sides with tomato mixture (you will probably have some left over to spoon on later).
Cook loaf for 20 minutes, then cover with tin foil and cook for another 10 minutes. After cooking let cool for 10 minutes before cutting into it.