Whisk together the flour, tea and salt in a medium sized bowl.
Place the butter, icing sugar, and orange zest into the bowl of a stand mixer. Beat at medium speed until light and fluffy.
Reduce the speed to low, and gradually add the flour mixture. Stir until just combined.
Divide the dough in half and transfer each half to a piece of parchment paper.
Roll each dough half into a log shape about 1 1/4" in diameter. Wrap in parchment paper, twisting the ends shut, and place each log in a paper towel tube (see notes above on how to get an even shaped log). Refrigerate until firm (about 1 hour).
Pre-heat your oven 350°F.
Use a sharp knife to cut your dough logs into 1/4 inch thick discs.
Place cookies 1 inch apart on a parchment lined cookie tray.
Bake for 9-10 minutes or until the edges are barely golden.