Preheat oven to 425 degrees F. Line a large baking sheet with parchment paper and set aside.

In a large bowl, combine the ground chicken (or turkey), breadcrumbs, egg, oil, garlic, garam marsala, chili powder, turmeric, paprika, salt, and pepper. Using your clean hands, work the mixture until evenly combined.

Using a cookie scoop, scoop about 1 1/2 tablespoons of the mixture into your palms and roll it into a ball. Place the ball on the prepared baking sheet. Repeat with the rest of the mixture, spacing the meatballs out onto the baking sheet, about 2-inches apart.

Bake the meatballs for 18 to 22 minutes, flipping halfway through, or until cooked through.

While the meatballs are baking, make the sauce. In a large skillet or Dutch oven, melt the butter over medium heat. Add the onion and cook until tender, about 3 to 5 minutes.

Stir in the tomato paste, ginger, garlic, garam masala, turmeric, chili powder, paprika, cumin, and cayenne pepper and cook until well combined, 1 to 2 minutes.

Stir in the tomatoes and chicken broth. Bring to a boil; reduce the heat and simmer, stirring occasionally, until sauce is slightly thickened, about 10 minutes.

Stir in the cream and lemon juice. Add the meatballs to the pan and cook until heated through, about 3 to 5 minutes.

Serve the meatballs and sauce with rice and naan, if desired.