Add yogurt, lemon, garlic, ginger, garam masala, salt, cumin, turmeric and black pepper to a medium sized bowl and stir to mix well.
Add chicken to marinade and stir to evenly coat. Cover and place in the refrigerator for at least 30 minutes (preferably 4-6 hours) and up to 24 hours.
While chicken is marinating (about an hour before you plan to grill), fill a flat baking dish with water and soak bamboo skewers for at least 30 minutes, preferably an hour, to prevent burning. (skip this step if using reusable metal skewers)
When chicken is done marinating, assemble kabobs by pushing a piece of chicken all the way through the pointy side of the skewer to the bottom, alternating with a piece of red onion, red pepper, or zucchini, between each piece of chicken. Make sure to leave a little bit of room between them as you are stacking so that everything will all cook evenly. Repeat until chicken and vegetables are used up.
Grill for 3-5 minutes per side until cooked through. Grilling time depends on how hot the grill is (mine was about 450° F; 332° C).
Serve immediately while warm. I typically serve over seasoned rice or potatoes. Enjoy!
Notes
You can use the marinade on whole boneless, skinless chicken breasts or thighs. For the most flavor, poke a few holes in each chicken breast or thigh using a fork and marinade for at least 4 hours, preferably overnight. Grill over high heat (breasts for 8-10 minutes per side and thighs for 6-7 minutes per side) until the chicken's internal temperature reads 165° F (73° C). Let sit for 10 minutes before serving.
To prepare kabobs in advance, let the chicken marinate for 20-30 minutes while prepping the veggies, then prepare the skewers and store refrigerated in a sealed container until an hour before grilling. Can be prepped 24 hours in advance.
To freeze chicken - prepare marinade and pour into a freezer safe bag. Add either chicken chunks or whole boneless skinless chicken breasts or thighs to marinade and use your hands to make sure chicken gets evenly coated. Freeze for up to 3 months. Defrost in refrigerator overnight for use the next evening.