Heat 2 tablespoons of oil in stock pot. Add onion and garlic, cook for 3 minutes. Add carrots, string beans, peas and potatoes. Cook for 5 minutes. Add stock and worcestershire. Season with salt and pepper. Bring to a boil, reduce the heat to medium low and simmer until the vegetables are tender about 15 minutes. Meanwhile, heat the remaining oil in a skillet. Add zucchini, spinach and tomato. Cook 3 minutes. Add to stock pot and simmer 5 minutes. Serve garnished with lime slices and sour cream on top.