Potato, Caramelized Onion, & Goat Cheese Gratin

Step 1: In a heavy 5- to 6-quart kettle heat oil over moderate heat until hot but not smoking and cook onions with thyme and salt and pepper to taste, stirring occasionally, until golden, about 15 minutes.

Step 2: Reduce heat to moderately low and cook, stirring frequently to keep from scorching, until golden brown. Remove kettle from heat.

Step 3: While onions are cooking, bring a large saucepan of salted water to a boil for potatoes.

Step 4: Peel potatoes and cut crosswise into 1/4-inch-thick slices.

Step 5: Add potatoes to boiling water and cook 5 minutes from time water returns to a boil.

Step 6: Drain potatoes well in a colander.

Step 7: Preheat oven to 425°F and lightly oil a 2- to 2 1/2-quart gratin dish or other shallow baking dish.

Step 8: Arrange half of potatoes, overlapping slightly, in dish and season generously with salt and pepper.

Step 9: Cover potatoes with onions, spreading evenly, and top with goat cheese.

Step 10: Arrange remaining potatoes, overlapping slightly, over cheese and season generously with salt and pepper.

Step 11: Dot gratin with butter.

Step 12: Gratin may be prepared up to this point 2 hours ahead and kept at room temperature, covered.

Step 13: Pour milk evenly over potatoes and bake 35 minutes, or until potatoes are tender and top is golden.

Step 14: Gratin may be made 1 day ahead and chilled, covered.

Step 15: Reheat gratin before serving.