Star chef Grant Achatz gives his rich, warmly spicy tikka masala a hit of fresh fruit flavor with a papaya-and-mango topping. Slideshow: More Crab Recipes
Tie the lemongrass, cardamom and cinnamon stick in a piece of cheesecloth.
In a large enameled cast-iron casserole, melt the ghee. Add the onions, ginger, garlic, garam masala, turmeric, coriander, cumin, paprika and cayenne and cook over moderate heat, stirring occasionally, until softened, about 10 minutes. Add the tomato paste and cook, stirring, until lightly caramelized, about 5 minutes. Add the lemongrass bundle along with the crushed tomatoes and their juices and bring to a simmer. Cover and cook over low heat, stirring occasionally, until thickened, about 30 minutes. Stir in the coconut milk and cook uncovered until the flavors meld, about 15 minutes.
Stir the crabmeat into the casserole, season with salt and cook until warmed through, about 2 minutes. Top with the mango, papaya, chopped cilantro, chopped mint and chile. Garnish with cilantro and mint sprigs and serve hot with rice and lime wedges.
The tikka masala can be prepared through Step 2 and refrigerated for up to 3 days. Reheat before proceeding.