Heat oven to 400℉, or preheat grill to medium-high. Spray a roasting pan or aluminum baking pans with cooking spray. Set aside.
In a small bowl, mix olive oil with all of the spices and herbs.
Remove stem of eggplant and slice into 1/2-inch slices. Place them on a baking cooling rack or a tray. Lightly salt tops and bottoms of eggplant rounds and allows to “sweat” for about 15 minutes. Mop up any liquid you see on top and bottom of the eggplant with a paper towel.
Prepare remaining veggies and toss with olive oil-seasoning mixture. Place veggies all in the roasting pan, or in the separate barbecue aluminum tins for cooking.
Roast veggies for about 25-30 minutes in the oven, until veggies begin to caramelize and become fragrant. They should be tender, but still in tact for this recipe.Remove from oven and cool.
If you plan to grill the veggies, place eggplant directly on the top rack of your grill, brush tops and bottoms with a little of the olive oil mixture and cook until tender and beginning to brown, flipping once during cooking. Remove from grill and set aside. Place the bell peppers and zucchini in one aluminum tin and the onions and tomatoes in another tin. Toss all of the veggies with the remaining olive oil mixture. Cook the peppers and zucchini on the top rack of the oven until tender and beginning to brown, turning once. Cook tomatoes and onions on the bottom rack of the grill, until cooked through and jammy, stirring often. Remove all veggies once cooked to a cutting board.
Once cooled, chop veggies coarsely and mix well. Spoon mixture to fill each of the hollowed tomatoes. This can be done several hours ahead of time and stored in a covered container in the refrigerator.