When you're a jet.

Continuing with the series of posts from musical theater listening quiz parties, we have the Poblano potatoes au gratin. This recipe was for "West Side Story", where I hosted a Puerto Rican inspired (or at the very least, Mexican) Thanksgiving. I couldn't imagine a more symbolic holiday for immigrants, and the fact that Gourmet (may it rest in peace) already planned it made that much easier to pull off.

We'll get to the rest of the menu eventually, but these potatoes were off the chain. I know that I put too many potatoes in and used some milk to make up for this, but they still managed to turn out. Friends who are "bad at cooking": Take note.

I had a gas stove in the apartment on Diamond street, so roasting the poblano peppers was easy. I know that there were pepper-ashes all over the stove for at least a week, but it was fun and fairly easy to do. When I discover a method to use with my electric oven, I'll be sure to pass it along.

This recipe was also another reason I love my mandoline slicer. Few things make me happier than a thinly-sliced vegetable. Invest in one as soon as humanly possible.

Finally, roasting the peppers, using the mandoline, and building the gratin are great technique builders. The recipe is fairly easy, but the dish looks and tastes impressive.

Poblano Potatoes Au Gratin

Serves 8

From Gourmet: In Mexican cuisine, rajas refers to thin strips of roasted chiles. Although they commonly spice up everything from stews to tamales, rajas are best when adding a kick to creamy dishes. Here, forest-green poblanos lend a mild, almost fruity heat to a potato gratin

• 1 1/2 pounds fresh poblano chiles (about 5)
• 1 pound onions, cut lengthwise into 1/4-inch strips
• 1 tablespoon vegetable oil
• 3 pounds large Yukon Gold potatoes
• 1 1/2 cups heavy cream
• 3/4 cup whole milk

Roast chiles and make rajas:
Roast chiles on their sides on racks of gas burners on high, turning with tongs, until skins are blackened all over, about 10 minutes. Immediately transfer to a bowl and let stand, covered tightly, 10 minutes.

When chiles are cool enough to handle, peel or rub off skin. Slit chiles lengthwise, then stem, seed, and devein. Cut lengthwise into thin strips.

Cook onions with 1 teaspoon salt in oil in a 12-inch heavy skillet over medium-low heat, stirring occasionally, until golden, about 8 minutes. Stir in chiles and remove rajas from heat. Reserve 1/2 cup rajas for topping.

Make gratin:
Preheat oven to 400°F with rack in middle. Generously butter a 3-quart shallow baking dish.

Peel potatoes, then cut crosswise into 1/16-inch-thick slices with slicer. Transfer to a small heavy pot. Add cream, milk, and 1 teaspoon salt and bring just to a boil over medium heat, stirring occasionally (liquid will thicken). Stir in rajas, then pour mixture evenly into baking dish. Sprinkle reserved 1/2 cup rajas on top.

Bake until potatoes are tender, 45 minutes to 1 hour. Let stand 15 minutes before serving.