Dry-Sauté the Veggies: Heat 1 tsp oil. Sauté the chopped onions, carrots, beans, and peppers with a pinch of salt for 3–4 minutes to remove moisture. Let cool completely.
Mix the Patty: Combine the cooled veggies with grated potatoes, grated cottage cheese, ginger, chilies, and all dry spices. Mix until it forms a dough.
Shape & Chill: Form into 4 thick discs (matching your bun size). Refrigerate for 15 minutes to firm up.
Char the Onions: Heat a skillet to high. Sear the thick onion rings with 1 tsp oil for 2 minutes per side until blackened at the edges. Splash with a drop of water to finish.
Blend the Sauce: Combine cottage cheese, yogurt, garlic, mustard, chili sauce, and ketchup in a blender. Process until it reaches a smooth, mayo-like consistency.
Grill the Patties: Brush a grill pan with a thin layer of oil. Grill the patties on medium heat for 4–5 minutes per side until deep grill marks appear.
Toast the Buns: Toast the buns with a tiny bit of butter until golden and crisp.
Assemble: Layer the bottom bun with sauce, ice-cold shredded lettuce, the hot grilled patty, charred onions, and a cold tomato slice. Add more sauce to the top bun and serve.