How to Make It
In a food processor, puree the strawberries until smooth; you should have 1 cup. Scrape the puree into a bowl.
In a small bowl, sprinkle the gelatin over 1/4 cup of the cream and let stand for 5 minutes.
In a small saucepan, stir 1/4 cup of the cream with the sugar over moderate heat until the sugar dissolves. Whisk in the gelatin mixture until dissolved; remove from the heat.
In a large bowl, combine the mascarpone and vanilla seeds. Using a handheld elecric mixer, beat the mascarpone at medium speed until thickened, about 3 minutes. With the mixer on, slowly drizzle in the gelatin mixture and beat for 1 minute. Fold in the strawberry puree.
In a large bowl, beat the remaining 1 1/2 cups of heavy cream at medium speed until stiff peaks form. Fold the whipped cream into the mousse and spoon into bowls. Refrigerate until well chilled, at least 1 hour.
In a medium bowl, toss the strawberries with the sugar and lime zest. Let macerate at room temperature for 20 minutes.
Spoon the strawberry salad and juices over the mousse and serve.