For the green paste, bring 2 inches of water to a boil in a large saucepan over high heat. Add the spinach and stir. Cover and steam, stirring every now and then, until wilted, about 5 minutes. Puree in a blender (with any remaining water) along with the cilantro and mint leaves. Set aside.
Heat the oil with the cinnamon stick, cardamom, and cloves in a large, heavy-bottomed casserole over medium-high heat and cook, stirring, until the cinnamon unfurls, about 2 minutes.
Add the garlic and ginger and cook stirring, 1 minute. Add the onion, green chile, and salt and cook, stirring, until the onion begins to brown around the edges, 8-10 minutes.
Stir in the beef and black pepper and cook, stirring, 5 minutes. Add the yogurt 2 tablespoons at a time and stir well after each addition. Simmer gently, stirring every now and then, for 5 minutes. Add the green paste, bring to a boil, reduce the heat and simmer 5 more minutes.
Stir in the garam masala and cook 1 more minute. Taste for salt, Serve hot.