Since I really love both of these vegetables and I wanted something different from the usual zucchini or tomato recipe, this combination was the end result of my experimenting. Zucchini is such a "social" vegetable and it pairs well with the tomato. This is great for social gatherings!
Wipe zucchini clean; slice off the ends. Cut into coin slices, then dice. Place in a colander to drain.
Wipe tomatoes and cut a thick slice from the top of each one. Scoop out the pulp. Dice the pulp and add to the colander with the zucchini to drain a few minutes. This will lessen your cooking time.
Wipe mushrooms and chop. Set aside in small bowl.
In a large heavy skillet, melt your butter or heat the olive oil if using that over medium heat. Add onions, garlic, and mushrooms stirring to coat. Saute' 2-3 minutes.
Spoon in zucchini and tomato pulp. Sprinkle sugar over mixure. Add salt, pepper, Italian seasoning and basil. Stir to blend well.
Cook mixture over medium to medium high heat, stirring frequently, until most of the liquid evaporates.
Stir in toasted croutons.
Line a 9 x 13-inch baking dish. Grease it so tomatoes will not stick to the bottom. Place tomatoes in dish and add the filling to each one. Do not cover with foil.
Bake in a preheated 350 degree oven for 15 minutes. Remove from oven and sprinkle the Mexican blend shredded cheese evenly over the tomatoes. Return to the oven and bake 5 more minutes or until cheese is browned.