Thinly slice 1 large onion, heat a large fry pan with a medium heat and add in 2 tbsp extra virgin olive oil, after 2 minutes add in the sliced onions and mix with the olive oil, after 5 to 6 minutes and the onions are soft and translucent turn off the heat, season the onions with ½ tsp dried thyme, sea salt & black pepper, mix until well combined and set aside
Spread some butter or margarine at room temperature onto 4 slices of bread, add 2 of the slices butter side down onto some parchment paper, add 1 slice of havarti cheese on top of each bread, 1 slice of cheddar cheese, evenly divide the grilled onions on top, add 1 slice of swiss cheese, a dash of sweet smoked paprika, 1 last slice of havarti cheese and crack in some fresh pepper, place the other 2 slices of bread over each sandwich butter side up
Heat a large nonstick fry pan with a low to low-medium heat, after 3 minutes add in a kiss of extra virgin olive oil and add both sandwiches into the pan over the olive oil, after 3 to 4 minutes gently flip the sandwiches to cook the other side, gently push down on each sandwich so everything is compact, but don´t over push them down, after a total cooking time of about 7 minutes, remove from the pan and serve at once, enjoy!