STRAWBERRY SOUFFLé

Steps:

• Remove wire racks from oven and place a baking sheet directly on oven floor. Heat oven to 425 degrees. Generously butter a 1 1/2-quart soufflé dish. Coat bottom and sides thoroughly with sugar, tapping out excess. To get the best rise, make sure there is sugar covering all of the butter on the sides of the dish.
• In a medium bowl, toss berries with 1/3 cup sugar and vinegar. Let stand for at least 30 minutes.
• Drain berries in a sieve set over a bowl, reserving juices. If less than 1/4 cup, add water to total 1/4 cup liquid.
• In a small saucepan, combine 2/3 cup sugar with berry juices. Bring to a boil over high heat, swirling occasionally, until sugar is completely dissolved. Cover pan and continue to boil until sugar reaches 235 degrees on a candy thermometer (soft ball stage), about 1 minute.
• Fold drained berries into hot syrup and bring mixture back to a boil, about 1 minute. Drain berries again, again reserving juices. Return juices to the saucepan and boil until thickened, adding any accumulated juices in the bowl of berries as you go, about 3 minutes. Remove from heat, fold in berries and lemon zest, and set aside to thicken and cool slightly.
• In the bowl of an electric mixer, beat egg whites until foamy. Add salt and cream of tartar and gradually increase speed to high. Add remaining 2 tablespoons sugar, a tablespoon at a time, and continue beating until egg whites hold stiff, glossy peaks. Immediately add berry mixture to one side of the bowl and quickly but delicately fold together. Transfer batter to prepared dish. Rub your thumb around the inside edge of the dish to create about a 1/4-inch space between the dish and the soufflé mixture.
• Transfer dish to baking sheet in the oven. Bake until soufflé is puffed and center moves only slightly when dish is shaken gently, about 10 to 12 minutes. Bake it a little less for a runnier soufflé and a little more for a firmer soufflé. Serve immediately.