Before you begin: Preheat the oven to 350°F and toast the slivered almonds for 6-8 minutes, until lightly golden. Cool completely.
Meanwhile, using a heat proof bowl over a pot of simmering water, or a double boiler, melt together the chocolate chips and vegetable shortening until the chocolate is completely smooth.
While the chocolate is melting, line a baking sheet with wax paper, and spread the pretzel crisps evenly on the paper.
Sprinkle the marshmallows and 3/4 cup of toasted almonds over the pretzel crisps. Chop the remaining almonds to sprinkle on top.
Pour the chocolate on top and using an offset spatula or the back of a spoon spread it covering everything evenly.
Sprinkle with remaining chopped almonds and place the pan into the refrigerator for 2 hours or until set.
Cut or break into pieces.