Lightly score the flesh of the chicken drumsticks and then put them into a large bowl. Mix together the yogurt, tikka masala paste, garlic, ginger and garam masala. Season, then pour the marinade over the chicken. Mix well to coat the meat completely, then cover and chill overnight.
Preheat the oven to gas 6, 200°C, fan 180°C. Cover a baking tray with foil and arrange the drumsticks on the lined tray. Cook in the oven for 45-50 minutes. Meanwhile, mix the raita ingredients and season to.