1. Preheat the oven to 425°F. Line a large baking sheet with parchment paper.
2. In a large bowl, combine the hash browns, 2 tablespoons of the melted butter, the onion, ½ teaspoon of the salt, and the pepper. Spread the hash brown mixture into an even layer on the prepared baking sheet and bake for 20 minutes. Move the sheet directly under the broiler and switch the oven to broil. Broil for 1 to 2 minutes more, until the hash browns are lightly crisped and golden.
3. Form the “biscuits” by filling a 4-inch biscuit cutter with one-quarter of the baked hash browns. Repeat with the remaining hash browns to make 4 “biscuits” total. Set aside.
4. In a small bowl, combine the mayonnaise, relish, and tomato paste. Set aside.
5. In a blender, combine the egg yolks, lemon juice, and hot sauce. With the blender running on low speed, very slowly drizzle in the remaining 8 tablespoons (½ cup) melted butter. Blend until the hollandaise sauce has thickened slightly, about 2 minutes. Set aside.
6. To assemble, lay the slices in a medium skillet over medium-low heat. Add 2 tablespoons of water and cook until the pastrami is heated through, 1 to 2 minutes. Transfer the pastrami to a paper towel–lined plate.
7. Layer each hash brown “biscuit” with 1 tablespoon of the Reuben sauce, a tomato slice, ¼ cup of the baby spinach, ¼ cup of the sauerkraut, one-quarter of the pastrami, and a poached egg. Drizzle with the hollandaise, sprinkle with the smoked paprika, and serve.
Tip: Beware of added artificial colors, high-fructose corn syrup, and chemicals when purchasing sweet pickle relish and frozen hash browns!
Tip: To poach the eggs, fill a stockpot halfway with water, add a dash of white or apple cider vinegar, and bring the water to a low simmer. Crack each egg individually into a small cup. Gently stir the simmering water to create a whirlpool motion in the pot and slowly pour in one egg at a time (don’t crowd them). Cook the egg(s) for 3 to 4 minutes and remove with a slotted spoon. Place the poached eggs on paper towels to soak up any additional water.
1. In a tall, wide-mouth mason jar or similar container, combine the olive oil, egg, Dijon mustard, lemon juice, and salt. Let the ingredients settle for a moment.
2. Place an immersion blender directly over the egg and begin to blend. Leave the blender in place for 5 seconds as the oil and egg begin to emulsify, then start to very slowly move the blender up and down until the oil and egg are fully emulsified, about 30 seconds. Cover and store in the refrigerator for up to 1 week.