Saag Gosht (Beef in Fragrant Spinach Sauce)

Name: Saag Gosht (Beef in Fragrant Spinach Sauce)
Cuisine: Indian
Ingredients: 2 10-oz boxes of frozen chopped spinach (or equivalent, about 2 cups, cooked and chopped); 4 T vegetable oil; 3 lbs boneless beef chuck* (see note below) or lamb -- cut in 1½-inch pieces; 3½ cups onions -- thinly sliced; 2 T garlic, minced; 3 T fresh ginger root, minced; 1 T ground cumin; 2 T ground coriander; 1 t turmeric; ½ 15-oz can of tomatoes, chopped; 3 green chiles, seeded and minced; 4 T plain whole fat yogurt; 1 cinnamon stick; 12 green cardamom pods; 9 whole cloves; 3 bay leaves; 1 T kosher salt, to taste; 3-4 t garam masala, to taste; cayenne pepper to taste