Mini Churros

Heat 1 3/4 inches oil to 400°F in a wide 3 1/2-to 4-quart heavy pot over high heat (oil will be just beginning to smoke). Drop in zest (oil will bubble vigorously) and fry until browned, about 1 minute.

Remove with tongs.

Line 2 trays with parchment paper.

Bring water with salt to a boil in a heavy medium saucepan, covered.

Add 2 teaspoons olive oil and remove from heat. Immediately add flour and stir vigorously with a wooden spoon until combined (mixture will be stiff and not very smooth). Fill churro-maker with some hot dough and wrap a kitchen towel around churro-maker canister.

Turn screw handle of churro-maker until dough emerges from star opening. Holding opening about 2 inches above a tray, turn handle to squeeze long lines of dough onto parchment.

Cut lines into 3-inch pieces with kitchen shears. Repeat with remaining dough, including any scraps.

Fry churros, 10 to 12 at a time, turning occasionally, until golden but still slightly moist in center, 3 to 4 minutes per batch.

Drain on paper towels. Return oil to 400°F between batches.

Roll warm churros in sugar and serve with warm chocolate sauce if desired.

•Churros can be piped, but not fried, 2 hours ahead and chilled, covered with plastic wrap, or 1 week ahead and frozen (first on baking sheets, then stored in sealable bags); thaw 30 minutes before frying.•To make chocolate sauce, bring 1/2 cup heavy cream to a boil and remove from heat, then stir in 3 1/2 ounces finely chopped bittersweet chocolate until smooth.