Whisk flour, semolina, salt, ajwain, and pepper in a bowl. Add cold ghee and rub with fingertips until the mixture resembles wet sand, about 2 minutes.

Add water a tablespoon at a time and knead into a stiff, smooth dough. Cover and rest for 20 minutes.

Divide dough into 4 portions. Roll each into a thin ⅛-inch sheet, prick with a fork, and cut into 2-inch rounds or shapes.

Heat oil to 325°F (165°C). Fry mathri in small batches, turning once, until pale golden, 3 to 4 minutes. Drain on paper towels.

Cool the fried mathri completely on a wire rack, then serve or store in an airtight container.