Toast the English muffins and set aside.

Melt butter in a pan over medium heat.

Add the baby spinach and sauté for 2-3 minutes, until wilted.

Remove from heat and set aside.

Fill a pot with water and bring to a boil.

Add white vinegar to the water and reduce heat to a simmer.

Crack eggs into separate cups or ramekins.

Create a whirlpool in the water with a spoon and gently pour eggs into the center of the whirlpool.

Poach eggs for 3-4 minutes, or until desired doneness is reached.

Remove eggs from water with a slotted spoon and drain on a paper towel.

To make the Hollandaise sauce, melt unsalted butter in a saucepan over low heat.

Whisk egg yolks and lemon juice together in a bowl.

Add melted butter to the egg mixture slowly, whisking constantly, until the mixture thickens.

Season with salt and black pepper to taste.

To assemble, place a toasted English muffin on a plate.

Add a layer of sautéed spinach on top of the muffin.

Place a poached egg on top of the spinach.

Spoon Hollandaise sauce over the egg and garnish with additional salt and black pepper.