- 6 tablespoons (about) butter
- 3 cups finely chopped leeks (white and pale green parts only; from 3 large leeks)
- 1/2 teaspoon dried thyme
- 1 1/2 teaspoons sugar
- 1 1/4 pounds Yukon Gold potatoes, peeled, coarsely grated, squeezed dry in kitchen towel
- 4 ounces thinly sliced Black Forest ham, cut into 1×1/4-inch strips
- 1/4 cup all purpose flour
- 1 large egg, beaten to blend
- 1 teaspoon salt
- 1/2 teaspoon ground black pepper
- Melt 2 tablespoons butter in large nonstick skillet over medium heat. Add leeks and thyme; sauté until leeks begin to soften, about 4 minutes. Cover; reduce heat to low. Cook until leeks are tender, stirring often, about 8 minutes. Add sugar; sauté uncovered until leeks are very soft, about 4 minutes. Transfer to medium bowl; cool. (Can be made 6 hours ahead. Cover; chill. Bring to room temperature before using.)
- Preheat oven to 250°F. Place large rimmed baking sheet in oven. Mix potatoes, ham, flour, egg, salt, and pepper into leek mixture in medium bowl. Melt 2 tablespoons butter in large nonstick skillet over medium heat. Working in batches, add potato mixture by 1/4 cupfuls to skillet; flatten each to 3- to 3 1/2-inch round. Sauté until brown and cooked through, about 4 minutes per side. Transfer potato cakes to baking sheet and keep warm in oven while preparing remaining potato cakes. Add more butter to skillet as needed for each batch. (Potato cakes can be made 2 hours ahead. Let stand at room temperature. Before serving, rewarm in 250°F oven about 10 minutes.) Serve hot.