In a small bowl, combine the mayo, Dijon mustard, Parmesan cheese, salt, and pepper. Mix well to create a creamy and flavorful spread.

Prepare your cheese station – lay out the Havarti slices and have the shredded cheddar readily available.

Spread the magic concoction generously on one side of each bread slice. Top one slice with a Havarti cheese slice, then sprinkle with some shredded cheddar. Repeat with the remaining bread slices,creating cheesy goodness between both slices.

Drizzle a little oil on a plate and rub it onto the outside of each assembled sandwich – this helps achieve that perfect golden brown crust.

Place a pan over medium-high heat and add a drizzle of oil. Once hot, carefully place your sandwiches in the pan.

For melty cheese perfection, add 1 tablespoon of cold water to the pan. Immediately cover the pan with a lid. The steam will work its magic, melting the cheese beautifully.

Keep an eye on your sandwiches! Once the cheese is melted and the bread is golden brown and crispy on the outside, it's time to enjoy! Carefully remove the lid and transfer your masterpieces to plates.

Cut your sandwiches in half (or not!), grab your favorite dipping sauce, and savor the symphony of flavors in every bite!