Preheat your oven to 220°C (430°F) and line a baking sheet with parchment paper or a silicone mat.
Cut the paneer into 1-inch cubes, keeping them firm but not too thick, so they bake evenly and develop a nice char.
In a mixing bowl, whisk together the Greek yogurt, garam masala, turmeric, chili powder, lemon juice, and oil until smooth and fragrant, about 30 seconds. This will be your marinade.
Add the paneer cubes and chopped bell pepper (if using) to the marinade. Gently toss to coat each piece thoroughly. Let sit for at least 30 minutes to soak up the flavors.
Thread the marinated paneer and peppers onto skewers, leaving space between pieces for even cooking and browning.
Place the skewers on the prepared baking sheet. Bake in the oven for 15-20 minutes, turning halfway through, until the edges are golden brown and slightly charred, releasing a smoky aroma.
Check for doneness: the paneer should be crispy on the outside with a caramelized, golden hue, and the aroma should be smoky and inviting.
Remove the skewers from the oven and let rest for 2-3 minutes. Optionally, brush with a little melted butter or extra lemon for added flavor and shine.
Garnish with chopped cilantro or a squeeze of lemon, then serve hot with green chutney or your favorite dips for a satisfying snack or appetizer.