Preheat oven to 170°c - 340°f. Grease a large baking dish with spray oil or butter.
Place a pan over medium-high heat. Add in the bacon and fry for 2 minutes. Add in the spinach and fry for 1 minute or until wilted. Season to taste, remove, and let cool.
In a bowl, add in the eggs, cream, bacon, and spinach mix and season to taste. Whisk to combine.
Pour the mixture into the greased baking dish and bake for 12 to 15 minutes or until lightly firm and fluffy. Remove and let cool for 10 minutes. Slice into 6 even-sized pieces.
Toast the English muffins under the grill/broiler for 2-3 minutes or until lightly toasted. Remove and spread with butter.
Place the egg, cheese, and relish into the toasted muffins, and place into the oven under the grill/broiler for 2-3 minutes or until the cheese has melted, and remove.
Wrap the muffins, eat them straight away or store them. DIg in.