Heat Rosemary Olive Oil in a large pot over medium heat. Stir in leeks and onions, and cook until the onion softens and turns translucent, about 5 minutes. Add potato, squash, carrots, apple, and chicken stock. Season with ½ teaspoon of Spicy Caribbean Chicken Rub to start. Bring to a boil, then reduce heat to medium-low, cover, and simmer until the vegetables are soft, about 20 minutes.