Start by preheating your oven to 200°C (or 400°F). This sets the stage for that perfect baking environment.

In a pan over medium heat, pour a splash of olive oil. Add the finely sliced red onion and sauté until it softens—about 5 minutes. Then, toss in the sage leaves and cook for another minute. The fragrant oils from the sage will fill your kitchen with an incredible aroma.

After that, squeeze the sausage meat from its casings into the pan. Break it up with a wooden spoon and cook until it's browned and cooked through. Stir in the breadcrumbs and freshly grated nutmeg; mix well to combine. Set it aside to cool slightly.

On a floured surface, roll out the puff pastry into a large rectangle. The goal is to make it even and shaped correctly for wrapping the filling.

Once the filling has cooled a bit, place it in a line down the center of the pastry. Leave space at the edges for sealing. If you’re feeling adventurous, add a bit of Dijon mustard along the filling.

Fold the pastry over the filling, ensuring it’s tightly wrapped. Press the seams to seal the edges. You can use a fork to crimp the edges for added security.

Slice a few vents on the top of the sausage roll to allow steam to escape. Then, brush the top with the beaten egg and a splash of milk. This will give it that golden look once baked.

Place your sausage rolls on a baking tray lined with parchment paper. Bake in the preheated oven for about 25–30 minutes until golden and crisp. You might want to stand close to the oven as they bake; your kitchen will smell divine!

Once out of the oven, allow the sausage rolls to cool slightly. Then, slice into pieces and serve warm.