Make the Panna Cotta:

• Measure ¼ cup prosecco in a measuring cup and gently whisk in the packet of gelatin. The mixture will begin to foam. Let stand for 3 minutes.
• In a medium saucepan over medium-high heat, combine the heavy cream, sugar, and salt. Cook the mixture gently until steaming but not boiling.
• Whisk in the gelatin and stir until it's melted. Add one drop of red food coloring and stir to combine.
• Remove from the heat and pour in the remaining ½ cup of Prosecco,and gently stir.
• Let cool on the stovetop until you can safely touch the side of the saucepan, about 30 to 40 minutes.
• Equally divide the panna cotta mixture among serving glasses or dessert cup dishes. Chill at least 3 hours, until set. This can be made 24 hours in advance.
• To Serve: Remove panna cotta from the refrigerator. Serve with a fresh berry sauce by carefully spooning it onto the top of the panna cotta. Serve with fresh berries on the side.