Take 250 grams of soya chaap and boil it in water for 10-15 minutes. Drain the water and let the chaap cool down.
In a mixing bowl, add 200 grams of thick curd, 1 teaspoon ginger-garlic paste, 1 teaspoon red chili powder, 1/2 teaspoon turmeric powder, 1 teaspoon garam masala, 1 teaspoon chaat masala, 1 teaspoon kasuri methi, salt to taste, and 2 tablespoons of mustard oil. Mix well to make a smooth marinade.
Add the boiled soya chaap to the marinade and mix well, ensuring that the chaap is well coated. Let it marinate for at least 30 minutes.
Preheat a grill or tandoor to medium heat. Skewer the marinated soya chaap and grill for 10-12 minutes, turning occasionally, until it is cooked and has a slightly charred appearance.
Serve hot with mint chutney and onion rings.