In a bowl, add the yogurt, garlic, ginger and all the dry spices for the chicken tikka and mix until well combines. Add the cilantro leaves and stir.
Place the chicken cubes in a storage bag; add the yogurt and spice sauce. Make sure all the chicken is covered by the sauce. Refrigerate to marinate for al least 30 minutes, but no more than 2 hours.
Preheat the oven to 350˚F and cover two baking sheets with parchment paper or silicon mats.
In a bowl, combine all the ingredients for the masala (but the tomatoes, the crème fraîche, salt and cilantro leaves), and stir to combine. Spread this mixture in one of the baking sheets.
Place the chicken pieces one by one in the other baking sheets.
Place both baking sheets in the me medium rack of the oven and bake for 30 minutes. In the case of the veggies, stir twice during the process.
Put the oven in low broil temperature, and broil for 3-5 minutes until the chicken is golden brown and the veggies are well done. Take both sheets out of the oven.
Place the roasted veggies in the vase of a blender, add the tomatoes and liquefy until thick and smooth.
In a cauldron or deep pan over medium heat, add the masala, salt and crème fraîche and stir.
Add the chicken and combine. Cook for 5 minutes.
Serve over a bed of basmati rice and sprinkle with fresh cilantro leaves.