1. Combin semolina and all-purpose flours in a bowl with the salt.
2. Using your fingers, swirl ingredients together until combined.
3. Gather flour mixture into a pile, and create a well in center. Pour 1/2 cup water into well.
4. Gradually incorporate flour mixture into water using your fingers.
5. Once all the water is absorbed, continue adding water, 1 tablespoon at a time, until mixture begins to form a dough.
6. Start to gather and knead dough, working it until no dry flour remains on work surface.
7. Continue to knead until smooth and elastic, about 5 minutes.
8. Divide dough into 16 equal portions, and cover them with a clean, damp kitchen towel.
9. Roll 1 portion of dough into an 18-inch-long rope.
10. Use a knife to cut and drag a 1/3-inch piece of dough from end of rope facing you -- a grainy wooden cutting board helps grip the dough.
11. Holding knife at a 45-degree angle to work surface, press and roll dough toward you.
12. Unfurl each piece of dough over your thumb in the opposite direction to form a concave shape, and transfer to a rimmed baking sheet lightly sprinkled with semolina flour. Repeat with remaining dough. Orecchiette can be stored at room temperature in a single layer overnight; cover with a clean kitchen towel or plastic wrap. Or prepare pasta in boiling water and add to a sauce.