Add the flour, grated Gouda, herbs, and salt to the processor. Pulse briefly to combine. Add the cold, cubed Spreado and the egg yolk. Pulse in short bursts just until the mixture starts to clump together and form a dough. Important: Do not over-mix, or the spread will melt, and the dough will become oily.
Option B: Hand Mixing Method
In a large bowl, mix the flour, herbs, salt, and grated Gouda. Add the cold, cubed Spreado. Use your fingertips to rub the spread into the flour mixture until it looks like coarse breadcrumbs. (Work quickly so as not to melt the spread too much). Add the egg yolk and mix with a spoon (or your hands) until a soft dough forms.
Tip the dough onto a lightly floured surface. Gently bring it together with your hands. Divide the dough in half and roll each piece into a log, roughly 4cm in diameter. (Optional: Roll the logs in sesame or poppy seeds now for a crunchy crust.)
Wrap the logs in plastic wrap and freeze the logs for 20 minutes (or refrigerate for at least 1 hour).
Meanwhile, preheat the oven to 180°C (160°C fan). Line 2 baking sheets with baking paper. Remove the logs from the freezer. Using a sharp knife, slice into 1cm thick discs.
Arrange on the baking trays (spaced 2cm apart). Bake for 15–18 minutes until the edges are golden brown.
Let them cool on the baking sheets for at least 5 minutes before moving them. They will be very fragile while hot, as they cool. Cool completely, and serve or store in an air-tight container.