How to Make It
Pour 1/4 cup Champagne into a small saucepan; sprinkle gelatin evenly over top. (It will become soft and absorb the liquid.) Heat mixture over low, stirring constantly, until gelatin dissolves completely.
In a large bowl, combine 6 tablespoons sugar and remaining 2 3/4 cups Champagne. It will foam, but the bubbles will subside after a minute. Stir in gelatin mixture, making sure it is evenly incorporated. Pour into a square or rectangular container so that the liquid is about 1 to 2 inches deep. Cover and chill in refrigerator until set, about 1 hour. The longer it chills, the more set it will become.
Shortly before serving, hull and quarter strawberries; toss with remaining 2 teaspoons sugar. Let stand 5 minutes, tossing occasionally to coat strawberries in juices.
Once gelée is set, use a knife to cut it into a crosshatch pattern in order to create small cubes. Top gelée cubes with macerated strawberries and serve.
Tartine All Day: Modern Recipes for the Home Cook, Lorena Jones Books, $40, copyright 2017.