Combine Lorna Dune cookies, sliced almonds, coconut and sugar in the bowl of a food processor. Pulse until mixture is coarsely chopped. Add butter and pulse a few more times to combine.
Dump cookie mixture into an 11-inch tart pan with a removable bottom**. Pat mixture up sides of pan forming a fairly thick edge. Pat remaining crumbs across bottom of pan.
Place pan in oven and bake crust for 12-15 minutes or until golden brown. Set aside to cool completely.
Whip the cream until soft peaks form when you lift the beater. Fold in the condensed milk, lime juice and lime zest (save a teaspoon for the top). Spread the filling into the pan evenly, swirling the top a bit. Sprinkle with reserved lime zest and refrigerate for at least 2 hours before serving. Serve with a dollop of whipped cream, a thin half slice of lime and a sprig of mint, if desired.
If you want to make this farther in advance (a week or two), just freeze it instead of refrigerating. Transfer from freezer to refridg a few hours before serving.