For the marinade: Mix together the yogurt, ginger, garlic, cardamom, flour, garam masala, cumin, chile powder, salt, to taste, lemon juice, and oil in a bowl.
For the skewers: Add the paneer, onion, and peppers to the marinade. Cover the bowl with plastic wrap and allow the paneer and vegetables to marinate for 30 to 40 minutes, or longer in the refrigerator.
Preheat the oven to 400 degrees F and oil a baking sheet.
Thread the vegetables and paneer alternately onto the skewers and place on the baking sheet. Bake the skewers in the oven for 7 minutes, drizzle over the melted butter, turn and cook for another 5 to 7 minutes, or until charred at the edges.
Sprinkle the skewers with chaat masala, and serve. The paneer skewers are also great served with green chutney.