Start by preparing the peaches. Peel and cut them into small pieces until you have about 3 cups. Place them into a blender or food processor, then immediately add 2 tablespoons of lemon juice. This keeps the color fresh and bright. Blend until you get a smooth puree, then set it aside in the blender jar for later.

In a small saucepan, off the heat, pour in 1/4 cup of cold water. Sprinkle the gelatin evenly over the surface and let it rest for about 5 minutes so it can bloom properly. Once softened, stir in the sugar. Place the pan over medium heat and warm gently, stirring only until the sugar dissolves, about 1 to 2 minutes. Do not let it boil or overheat. Remove from the heat straight away.

Pour this warm gelatin mixture into the peach puree and blend again until everything is fully smooth and combined. Cover and refrigerate the mixture for about 2 hours, until it begins to thicken slightly but is not fully set.

When the fruit mixture has started to thicken, whip the heavy cream until it forms stiff peaks. Take care not to overwhip. Gently fold the whipped cream into the peach base, working slowly until the texture becomes light, airy, and fully blended.

Spoon the mousse into 6 small ramekins or serving glasses, dividing it evenly. Place them in the refrigerator and allow them to set completely.

For the topping, place sliced peaches into a small saucepan with the sugar and lemon juice. Set over medium to medium-high heat and stir until the sugar dissolves. Bring it to a gentle boil, then let it simmer for about 2 minutes. Remove from the heat and allow it to cool fully before spooning over the set mousse.

Finish with a little fresh mint if you like, just for a touch of color and freshness.