Whisk flour, tea, and salt in a small bowl; set aside.
Put butter, sugar, and orange zest in the bowl of an electric mixer fitted with the paddle attachment. Mix on medium speed until pale and fluffy, about 3 minutes. Reduce speed to low; gradually mix in flour mixture until just combined.
Divide dough in half. Transfer each half to a piece of parchment paper; shape into logs. Roll in parchment to 1 ¼ inches in diameter, pressing a ruler along edge of parchment at each turn to narrow the log and force out air. Transfer in parchment to paper towel tubes; freeze until firm, 1 hour.
Preheat oven to 350 degrees. Cut logs into ¼-inch-thick slices. Space 1 inch apart on baking sheets lined with parchment.
Bake cookies, rotating sheets halfway through, until edges are golden, 13 to 15 minutes. Let cool on sheets on wire racks.
