Toss together first 4 ingredients.
Melt half of butter in half of oil in a large skillet over medium-high heat. Press half of potato mixture into bottom of skillet. Cook 5 to 7 minutes or until edges brown. Remove from skillet, and place on a lightly greased baking sheet. Repeat with remaining potato mixture, butter, and oil.
Bake at 400° for 10 to 15 minutes or until crisp and golden. Cut into wedges to serve.