Season both sides of the chicken breasts with salt, black pepper, and smoked paprika.
Heat olive oil in a skillet over medium heat. Add the chicken breasts and cook for 5-6 minutes on each side until golden brown and cooked through. Remove from skillet and set aside to rest.
While the chicken cooks, toast the English muffins until golden and crisp.
In the same skillet, melt the butter over medium heat. Crack the eggs into the skillet and cook until the whites are set but the yolks remain runny, about 3-4 minutes. Remove from heat.
Slice each cooked chicken breast into two pieces to fit the English muffins.
To assemble each sandwich, place one half of an English muffin on a plate. Layer with fresh spinach leaves, one piece of chicken, a slice of cheddar cheese, and a fried egg. Top with the other half of the English muffin.
Serve immediately while warm.