Persian Lamb Shanks

Name: Persian Lamb Shanks
Ingredients: 1/8 teaspoon ground saffron; 4 lamb shanks (12 to 16 ounces each); 1 large onion, peeled and quartered; 1 head garlic; 2 cinnamon sticks; 6 cardamom pods; 2 bay leaves; Kosher salt; 4 tablespoons unsalted butter; 2 tablespoons olive oil; 2 onions, finely chopped; 1/4 cup tomato paste; 1 tablespoon garlic powder; 1 teaspoon ground turmeric; Kosher salt and freshly ground black pepper