Heat ghee in a medium Dutch oven or pot over medium until shimmering, about 1 minute. Add onion and salt; cook, stirring occasionally, until onions are soft and translucent, about 3 minutes. Add tomato paste, garlic, ginger, 3 teaspoons red chili powder, garam masala, and turmeric; cook, stirring constantly, until fragrant, about 2 minutes. Add chicken, tomatoes (with juices), and chipotle chiles in adobo sauce. Stir to coat chicken in sauce, adding about ½ cup water if canned tomatoes didn’t have much liquid; you want about 1 cup liquid total. Cover and simmer over medium-low until chicken is cooked through, about 8 minutes.

Meanwhile, toast the cashews in a small skillet over medium, stirring often, until fragrant, about 3 minutes; transfer to a medium bowl. Add remaining 1 teaspoon red chili powder to cashews and toss to coat; set aside.

Uncover Dutch oven. If the sauce is watery, increase heat to medium and simmer until the sauce has thickened, 5 to 10 minutes. Stir in heavy cream. Transfer chicken and sauce to a serving dish and garnish with cashews. Serve hot.