Step 1

In a medium bowl, combine yogurt, ¼ cup tahini, olive oil, lemon juice, salt and pepper. Add chicken and mix to combine well.

Step 2

Divide chicken mixture evenly between two slices of bread. Top chicken mixture with even parts onion, tomato, and spinach. Spread the remaining 2 teaspoons tahini evenly over the remaining 2 slices of bread; close each sandwich with bread slices, tahini side down. Serve immediately or wrap in plastic and refrigerate until ready to serve, up to 2 days.