Sauté Aromatics: Gently warm the olive oil in a small frying pan over medium-low heat. Add the finely sliced red onion and sauté slowly for 3-4 minutes, or until softened and translucent but not browned. Remove from heat and set aside.

Prepare Cheese Mixture: In a mixing bowl, combine the grated sharp cheddar cheese, the two large egg yolks, Worcestershire sauce, English mustard powder, and smoked paprika. Stir in the cooked onions until everything is well incorporated.

Initial Toast: Arrange the 4 slices of low-carb seeded bread on a baking sheet suitable for your broiler/grill. Lightly toast one side of each slice under a preheated medium broiler/grill setting for 1-2 minutes, watching carefully to prevent burning.

Assemble and Final Grilling: Remove the bread from the broiler/grill. Turn the slices over to the untoasted side. Evenly divide and spread the prepared cheese and onion mixture over the untoasted side of each slice.

Grill to Perfection: Return the baking sheet with the topped bread to the broiler/grill. Cook for another 3-5 minutes, or until the cheese mixture is fully melted, bubbling, and has achieved a rich golden-brown colour on top. Keep a close eye to prevent charring.

Serve: Carefully remove The Ultimate Viking Keto Melts from the broiler/grill. Allow to cool for a moment before serving. Each serving consists of two topped slices. These are delicious served immediately, either on their own or accompanied by a fresh green salad or avocado slices.