In a medium bowl, combine trout, onion, garlic, mayo, mustard and black pepper, stirring to combine.
Toast the english muffins in the toaster until just browned.
Evenly spread the trout mixture over the muffins, topping with a slice of cheddar and a slice of tomato.
Set the oven to broil, and broil the melts for 6 minutes, or until the cheese is melted and the tomato is steamy. You can go longer to get the cheese to caramalize, but watch very closely so that the bread doesn’t burn!
Recipe by Alison's Allspice at https://www.alisonsallspice.com/smoked-trout-melts/