Kidney Bean Stew with Sweet Potatoes and Oranges

2 tablespoons grapeseed oil 2 bay leaves 2 tablespoons finely chopped fresh ginger 2 tablespoons finely chopped fresh garlic 2 tablespoons cumin seeds 1 tablespoon garam masala 1 teaspoon fenugreek seeds 1 teaspoon dried oregano 1 teaspoon dried rosemary 1 teaspoon turmeric 1 teaspoon salt 2 tablespoons tamarind pulp* 1 (14-ounce) can crushed tomatoes (about 1 1/2 cups) 2 cups diced sweet potato 1 cup water 1 (14-ounce) can kidney beans, drained (about 1 1/2 cups) 2 small seedless oranges, peeled and cubed *Can be found at specialty Asian and Indian markets.