How to Make It
Place 1 tablespoon oil and 1 teaspoon butter in a large, high-sided skillet over medium-high; cook until butter foams. Add half of leeks, cut side down; cook 5 minutes, pressing leeks occasionally, until cut sides are deeply browned. Remove leeks from pan. Repeat procedure with remaining oil, butter, and leeks.
Return all leeks to pan; add wine. Reduce heat to medium-low; cover and simmer 20 minutes or until leeks are tender when pierced with a fork. Stir in salt and pepper. Transfer mixture to a platter; top with Parmesan cheese.