In a large bowl, combine the yogurt, lemon juice, ginger-garlic paste, paprika or chili powder, ground cumin, ground coriander, turmeric powder, garam masala, salt, and vegetable oil. Mix well.

Add the chicken pieces to the marinade and coat them evenly. Cover the bowl and refrigerate for at least 2 hours, or preferably overnight to let the flavors penetrate the chicken.

If using a grill, preheat it to medium-high heat. If you don't have a grill, you can also use an oven. Preheat the oven to 200°C (400°F) and line a baking sheet with aluminum foil.

If you're grilling, thread the marinated chicken pieces onto skewers. Leave a little space between each piece for even cooking.

If grilling, place the skewers on the preheated grill and cook for about 10-12 minutes, turning occasionally, until the chicken is cooked through and has charred edges.

If baking, arrange the chicken pieces in a single layer on the prepared baking sheet. Bake in the preheated oven for 20-25 minutes or until the chicken is cooked through, flipping halfway through.

Once cooked, remove the chicken tikka from the grill or oven and let it rest for a few minutes.

Serve hot with sliced onions, lemon wedges, and mint chutney or your favorite dipping sauce. You can also serve it with naan bread or rice for a complete meal.