Unroll the thawed phyllo dough, keeping the dough you aren't using covered so it doesn't dry out. Fold each rectangle of phyllo in half, and cut this rectangle in half, so that you have squares of phyllo that are two sheets thick.
Place a square of semolina pudding in the center of the filo dough square, and wrap the edges of the dough around the semolina like you are wrapping a present. Seal the edges with a little flour mixed with water to form a glue that will keep them from opening up while frying. Press down gently on this parcel to distribute the semolina inside, and repeat with the remainder of the filling.
Heat enough oil to fill a deep skillet about 1-2 inches over medium high heat. Once very hot, add as many tamriyeh as you can without overcrowding the pan. Fry 1-2 minutes a side until golden brown, then remove to a paper towel lined plate to absorb some of the excess oil.
Garnish fried tamriyeh with powdered sugar and pistachio powder. Enjoy hot!