The main ingredients of orechiette pasta are semolina flour, water and salt. Epicurious.com's recipe for orechiette also includes all-purpose flour. An orechiette noodle is round and flat, with a slight indent in the center.
Orechiette pasta is traditionally made without eggs, so the pasta tends to have a slightly firmer texture than egg pasta. The flat, indented shape of the noodles makes them an effective vehicle for various types of sauce.
To make Epicurious' recipe for orechiette, stir together 2 cups of semolina flour and 2 cups of all-purpose flour in a bowl. Form a well in the center of the flour and pour in 1 cup of lukewarm water. Add a generous pinch of salt. Use a fork to incorporate the water into the flour until a loose dough is formed. Move the dough to a work surface and knead until it becomes smooth and elastic, then divide the dough into eight pieces and wrap each piece in plastic.
Remove plastic wrap from an individual dough ball. Stretch the ball into a 1/2 inch wide rope and cut into rounds. Form a depression in each round by pressing into it with one thumb. Coat each orechiette noodle in semolina flour and place the noodles on towel-lined trays to keep them from sticking to each other before cooking.