Heat a large skillet over medium-high heat. Add the olive oil, spinach, garlic, and lemon juice. Cook until wilted. Transfer the spinach to a small dish and set aside.
Combine beef, salt, and pepper in a bowl. Mix together until incorporated and form into 4 patties.
Cook burgers in the same skillet used for spinach on medium-high heat for about 4-5 minutes per side until desired doneness. Set the burgers aside.
Toast the English muffins. (*see note for paleo english muffin option)
For the Hollandaise Sauce:
Combine egg yolks, lemon juice, butter, and cayenne in a blender. Blend until smooth and well combined. Season to taste with salt and pepper.
To assemble, place the burger on top of the English muffin. Place the spinach on top of the burger and a poached egg on top of the spinach. Spoon the Hollandaise sauce over top and serve while warm.