Slice the Chicken: Lay the breast flat and cut into very thin, wide slices at a slant. This ensures the chicken cooks instantly and stays juicy.
Initial Marinade: Toss the chicken with salt, vinegar, ginger-garlic-chili paste, and red chili powder. Let it rest for 20 minutes.
Prepare Chili Paste: Drain the soaked Kashmiri chilies and blend with a splash of water until you have a vibrant, smooth red paste.
Infuse the Oil: Heat oil in a wide, flat skillet (or Tawa). Add the minced garlic and sauté for 30 seconds until fragrant but not browned.
Build the Masala: Stir in the prepared chili paste. Reduce heat and add the whisked yogurt, spicy chili powder, garam masala, and salt.
The "Bhuna" Process: Sauté the masala on medium heat until the oil separates from the edges. Add a splash of hot water if it gets too dry.
Sear the Chicken: Arrange the chicken slices in a single layer over the masala. Cook on medium-high heat for 3–4 minutes without stirring.
The Flip: Flip the chicken pieces once the edges turn white. Ensure every slice is coated in the thick, spicy glaze.
Finish Cooking: Sauté for another 3–5 minutes, flipping occasionally, until the sauce reduces and clings ("Lapeta" style) to the meat.
The Glossy Finish: Stir in the chopped cilantro stems and leaves. Drop in the butter cubes and toss until the sauce is glossy and rich.
Serve: Plate immediately. Best enjoyed hot with a squeeze of fresh lime or as a filling for warm wraps.