Using a food processor or box grater, grate the onion. Place a fine mesh strainer over a bowl and then pour the onion puree into it. Press the puree with the back of a spoon and reserve the liquid that strains out.

In a medium bowl or large airtight storage bag, add lamb, onion liquid, yogurt, tomato or pepper paste, olive oil, paprika, red pepper flakes, black pepper, and salt. Using a spoon or your hands, combine all ingredients well. Cover or seal the container and transfer to the fridge. Allow the lamb to marinate for at least four hours or overnight.

The next day, soak medium bamboo skewers in cold water.

Place a medium pot on the stove and add butter and olive oil. Heat over medium heat and then add the diced onion. Cook, stirring occasionally for 2 to 3 minutes, just until the onion becomes translucent. Add the garlic, tomato, serrano pepper, red bell pepper and continue to cook for 3 to 4 minutes until softened. Add the tomato paste and continue to sauté for 1 additional minute. Add the bulgur, salt, and pepper, and stir until well combined. Add the chicken broth and cover with a lid. When the chicken broth begins to simmer, reduce the heat to low and cook for 10 to 15 minutes until the liquid is cooked out. Turn off the heat, leaving the pan on the burner, and remove the lid. Place a large paper towel over the top of the pan and then replace the lid. Allow to sit until the paper towel has soaked up all extra moisture.

Remove the lamb from the fridge and prepare your vegetables. Add one cube of lamb onto a skewer and then one piece of the bell peppers or onion, continuing to alternate the pieces. Fill each skewer, leaving 1-inch at the top and bottom. Place all the tomatoes and serrano peppers onto their own skewers. Repeat until all the pieces have been prepared.

In a medium bowl, add onion, olive oil, lemon juice, sumac, and salt. Stir to mix well and set aside.

Heat a grill or cast-iron skillet. Add the skewers onto the hot surface. Cook for 4 to 6 minutes on one side until well caramelized and then flip. Cook an additional 4 to 6 minutes, checking the doneness of the meat after 8 minutes to cook to your preference. 10 to 12 minutes total should cook the meat to medium. Remove from the heat.

Heat naan or pita bread over the grill or skillet and place on to the plates. Top with pilaf, kebabs, and sumac onion salad. Serve while warm.