Mix the garlic infused oil with 3 tbsp lactose free yogurt, the lemon juice, 1 tsp tomato purée, half the spices, and some seasoning in a medium bowl.
Add the chicken, toss, cover and chill in the fridge for at least 1 hr or overnight.
Make the chili sauce. Put 100g of the tomatoes, the whole red chili, the remaining spices and tomato purée, plus 1 tbsp olive oil and the molasses in a food processor.
Add some seasoning and pulse until puréed, then set aside.
Heat oven to 200C/180C fan/gas 6, and heat a griddle pan. Thread the chicken onto metal skewers or wooden ones that have been soaked, then wipe off the excess marinade.
Skewer the remaining tomatoes on a separate skewer. Lightly oil the griddle with the remaining olive oil and brown the chicken on both sides, then transfer to a baking tray and bake in the oven for 10 mins, or until cooked through.
Meanwhile, griddle the tomatoes for 1-2 mins, turning halfway through so they have griddle marks on both sides.
Serve the chicken and tomatoes on gluten free flatbreads with the remaining the remaining lactose free yogurt, parsley and coriander with the chili sauce spooned over.