In a bowl, whisk together the yogurt, garam masala, turmeric, chili powder, lemon juice, and mustard oil until well combined, creating a bright and thick marinade.
Add the paneer cubes to the marinade, gently tossing to coat each piece thoroughly. Cover and let marinate in the fridge for at least 1 hour, preferably longer to deepen flavors.
Soak wooden skewers in water for 30 minutes to prevent burning, or prepare metal skewers if using.
Thread the marinated paneer cubes onto skewers, alternating with slices of onion and bell pepper for added flavor and color.
Preheat your grill or broiler to medium-high heat. Place the skewers on the grill or under the broiler rack, leaving space between each for even cooking.
Grill or broil the paneer skewers for about 4-5 minutes per side, flipping carefully to develop a deep golden char and smoky aroma. Baste with additional marinade or oil if desired for extra flavor and moisture.
Once the edges are charred and crispy and the paneer feels hot and firm to the touch, remove the skewers from heat.
Serve hot, garnished with fresh lemon wedges and sliced onions for a refreshing crunch and extra zing.
