Cook vermicelli according to package directions; drain. Rinse with cold water; drain again. Set aside. Meanwhile, in a large skillet cook onion in hot butter over medium-high heat about 4 minutes or until onion is tender. Add lemon juice, ginger-garlic paste, the 2 teaspoons garam masala, 2 teaspoons cumin, and the chili powder; cook and stir for 1 minute. Carefully stir in tomato puree; cook and stir for 2 minutes. Stir in yogurt, cream, cayenne pepper, and salt. Stir in chicken; reduce heat to low. Simmer, uncovered, for 10 minutes, stirring frequently. Remove from heat; set aside.
In a large bowl combine three-fourths of the cheese, the spinach, cream cheese, the 1 teaspoon garam masala, 1 teaspoon cumin, and the turmeric; set aside.
Preheat oven to 350 degrees F. Transfer half of the chicken mixture to a buttered 3-quart round casserole. Top with half of the vermicelli. Spread the spinach mixture evenly oven the vermicelli. Top with the remaining vermicelli and chicken mixture.
Cover and bake for 65 to 70 minutes or until heated through. Uncover and sprinkle with the remaining cheese. Bake, uncovered, for 5 minutes more.