Combine 1 1/2 cups flour, yeast, and salt in a large mixing bowl; stir well. Set aside.
Heat milk, sugar, and shortening in a small saucepan to 120° to 130°. Gradually add to flour mixture, beating well. Stir in enough remaining flour to make a stiff dough.
Turn dough out onto a floured surface, and knead 5 minutes or until dough is smooth and elastic. Place dough in a well greased bowl, turning to grease top. Cover and let rise in a warm place (85°), free from drafts, 1 hour or until doubled in bulk.
Punch dough down; divide into 24 equal portions. Roll each portion into a ball, and place on buttered baking sheets; press clown lightly with fingertips to resemble a bun. Brush rolls with melted butter, and sprinkle with poppy seeds. Cover and repeat rising procedure 30 minutes or until doubled in bulk.
Bake at 400° for 15 minutes or until golden brown. Remove from baking sheets immediately. Cool completely. Split and use as party sandwich buns.