Marinate chicken: Combine yogurt, ginger + garlic, garam masala, cayenne, black pepper, and salt. Add chicken cubes and toss to coat. Cover and marinate in the refrigerator for 30 minutes or up to 24 hours. Remove chicken from fridge and thread onto kabob skewers. Grill chicken in a 450F pre-heated oven under the broiler for 15-20 minutes or on an outdoor grill or griddle pan until chicken is charred in center is tender.
To make the sauce: While the chicken is cooking, prepare the sauce. Heat a large heavy-duty pan to medium/high heat. Add oil, butter, and onion. Cook until onion begins to brown. Add the jalapeno, garlic, ginger and cook for 2 minutes or until garlic begins to brown. Add the tomatoes, tomato paste and spices. Cook for 5 minutes. Pour in 1 cup of water and allow mixture to simmer on a low/medium heat for 15 minutes. Add cream and cook for just 2-3 minutes. Mix in the cooked chicken and stir to coat.
To make naan bread:Combine the butter and garlic in a small bowl. Set aside. Divide pizza dough into 8 equal portions. Roll the dough to a small circle using a rolling-pin. Heat up a skillet (cast-iron preferred) over high heat and lightly grease the surface with some oil to avoid the dough from sticking to the skillet. Place the dough on the skillet. When it puffs up and bubbles and burnt spots appear, flip it over and spread with the garlic butter mixture. Cook until done. Repeat the same until all dough are done.
To make 2 tablespoons garam masala (1 for marinade and 1 for sauce) combine 1 1/2 teaspoon ground cumin 1 1/2 teaspoons ground coriander 1 teaspoon ground cardamom 1 teaspoon ground black pepper 1 teaspoon ground cinnamon.