Mix Ingredients:

• In a small bowl, whisk together Thousand Island dressing, Dijon mustard, dill, pickle relish, and lemon juice.

• Adjust seasoning with salt and pepper to taste.

• Cover and refrigerate until ready to serve.

Preheat the Oven:

• Preheat oven to 400°F (200°C) and line a baking sheet with parchment paper.

Prepare the Pastry:

• Unroll the thawed puff pastry on a lightly floured surface.

• Use a rolling pin to smooth out any creases and create a uniform rectangle.

Spread the Mustard:

• In a small bowl, mix the Dijon mustard and whole grain mustard.

• Spread the mustard mixture evenly over the puff pastry, leaving a 1/2-inch border around the edges.

Layer the Pastrami and Cheese:

• Lay the pastrami slices evenly over the mustard layer, overlapping slightly.

• Follow with a layer of Swiss cheese slices, covering the pastrami.

• Sprinkle with a pinch of black pepper for extra flavor.

Roll the Pastry:

• Starting from the long edge, carefully roll the puff pastry into a tight log.

• Wrap the log in plastic wrap and chill in the refrigerator for 15 minutes to firm up.

Prepare the Egg Wash:

• In a small bowl, whisk together the egg and water to create an egg wash.

Slice the Pinwheels:

• Unwrap the chilled log and slice into 1/2-inch thick rounds using a sharp knife.

• Arrange the pinwheels on the prepared baking sheet, spacing them 1 inch apart.

Brush and Bake:

• Brush each pinwheel with the egg wash and sprinkle with poppy seeds (if using).

• Bake for 15-18 minutes, or until the pastry is golden brown and puffed.

Plate the Pinwheels:

• Transfer the pinwheels to a serving platter and allow them to cool for 5 minutes.

Serve with Dipping Sauce:

• Serve the pinwheels warm with the chilled dipping sauce on the side.

Garnish:

• Garnish with a sprinkle of fresh dill or parsley for added freshness and presentation.