- Preheat oven to 350°F (180°C).
- In food processor, pulse together Monterey Jack cheese, Parmesan cheese and butter until smooth. Blend in yolk and pepper. Pulse in flour just until soft dough forms.
- Place hazelnuts in shallow bowl. Place egg white in another shallow bowl. Roll tablespoons of dough into 1” (2.5 cm) balls. Dip in egg white; roll in nuts to coat. Transfer to parchment paper-lined baking sheets. With thumb, indent centre of each ball. Refrigerate for 15 minutes.
- Bake in centre of oven for 15 minutes or until firm and slightly golden. Let cool on pan on racks.
- Stir together sour cream and dill. Spoon into each indentation. Top with thin strip of smoked salmon.
Try different toppings on the shortbread thumbprints:
- Hot pepper jelly with sour cream topped with fresh coriander and smoked trout or crab.
- Sour cream with horseradish topped with thin sliver of rare roast beef.