1. Preheat oven to 425.
2. Heat oil in a large pan over high heat. Add the zucchini, peppers, garlic paste, 1/4 teaspoon red pepper flakes, salt and pepper, to taste, cook until almost soft, 5 minutes. Set aside cool.
3. Whisk together eggs and herbs in a large bowl. Add meat, bread crumbs, cheese, 1/2 cup of the ketchup, 2 tablespoons of the balsamic vinegar, and the cooled vegetables and mix until combined.
4. Mold the meatloaf on a baking sheet lined with parchment paper. Whisk together the remaining ketchup, balsamic vinegar, and red pepper flakes in a small bowl. Brush the mixture over the loaf. Bake meatloaf for 1 to 1 1/4 hours. Remove from the oven and let rest for 10 minutes then slice.