01 - Line an 8x4 inch loaf pan with parchment paper, allowing overhang on all sides for easy removal.
02 - Combine sugar and water in a medium saucepan over medium heat. Stir constantly until sugar completely dissolves. Bring to a gentle boil and cook without stirring until thermometer reaches 245°F (soft ball stage).
03 - In a mixing bowl, whisk tahini, matcha powder, and salt until completely smooth and uniform in color.
04 - Immediately pour hot syrup into tahini mixture. Stir vigorously with wooden spoon for 20-30 seconds until mixture thickens, appears matte, and begins pulling away from sides of bowl.
05 - Quickly scrape mixture into prepared pan. Smooth top with spatula or back of spoon.
06 - Let cool at room temperature for 10 minutes, then refrigerate for at least 1 hour until firm and set.
07 - Lift halva from pan using parchment overhang. Cut into squares and serve immediately or store refrigerated.