Comforting Flavorful Sweet Potato Curry with Apples and Chickpeas

Name: Comforting, Flavorful Sweet Potato Curry (with Apples and Chickpeas)
Ingredients: 2 medium sweet potatoes (peeled and cubed); 2 small cooking apples (peeled and cubed); 3/4 cup chickpeas (canned ones are fine); 1 medium white onion (finely chopped); 1 clove garlic (minced); 2 tablespoons extra virgin olive oil (or half coconut oil); 2 - 3 teaspoons (heaping) curry powder (or half mild, half spicy); 1 teaspoon black cumin seeds; 1/2 teaspoon ground cumin; 1/4 teaspoon dried and chopped lemongras; 1/2 teaspoon ground coriander; 1 inch pieces fresh ginger (minced); 2 - 3 cups water (amount depends on your preference); salt; pepper; 1/2 cup coconut milk (optional)