Prepare the herb paste: Process all herb paste ingredients in a food processor until smooth. Set aside.

Line a baking sheet with parchment paper. Place eggplant cubes on paper and sprinkle with 1 teaspoon salt. Bake at 400 F 10-12 minutes or until slightly softened.and dry. Set aside.

Place 2 tablespoons olive oil in a large skillet over medium-high heat. Heat oil until shimmering, then add potatoes and onion. Stir frequently until potatoes and onions become translucent. Clear the center of the pan and add 1 tablespoon olive oil and tomato paste. Stir until potatoes are evenly coated. Continue cooking over medium-high heat until lightly browned, about 2 minutes. Add water, chopped tomatoes, and reserved juice, and previously cooked eggplant. Bring to a boil, then reduce heat to medium, cover, and let simmer for 20 minutes, stirring frequently.

While the stew is simmering, heat remaining 1 tablespoon olive oil in a medium skillet, over medium-high heat. Add diced zucchini, red pepper, and 1/2 teaspoon salt to skillet. Cook over medium-high heat until vegetables are just tender. Clear the center of the pan and stir in herb paste until vegetables are coated. Cook 1-2 minutes longer until fragrant. Remove from heat and stir into potato-stew mixture until combined. Cover and let sit 20 minutes in order to let the flavors meld.

Just before serving, stir in chopped basil and season with salt to taste.