Combine all the ingredients for the marinade in a bowl and whisk well. Taste to see if you have enough salt. (Make sure to taste before you add the chicken!)

Cut the chicken into about 1-inch cubes and add into a large zip-top bag (or a glass food storage container for marinating). Add the marinade and mix well to make sure all the chicken is coated.

Let the chicken marinate for at least 2 hours or overnight. (Don't exceed 12 hours of marinating time.)

For the best results, cook the chicken kebabs on the grill.

If you will be using wooden skewers, make sure to soak them in water first for about 45 minutes.

Prepare the grill and preheat it to medium-high heat.

Skewer the chicken into the soaked skewers, fitting 4-5 pieces onto each skewer.

Grill the chicken kebabs for about 4-5 minutes per side, turning them a quarter of the way.

While chicken is cooking, lightly brush pita bread with olive oil and place them onto the grill to heat through.

Slice the vegetables and place them onto a serving dish.

To serve chicken souvlaki, top each warm pita bread with some grilled chicken, sliced onions, tomatoes, and tzatziki sauce.

You can easily cook the chicken souvlaki skewers in a preheated skillet on the stovetop.

Add some oil to the skillet and preheat it.

Place the chicken skewers in the pan in one even layer and don’t let them overlap.

Cook the chicken over medium to medium-low heat, turning it a quarter of the way every 3-4 minutes.

Cook just until the chicken is cooked through.