Heat oven to 400 F. Line a baking sheet with parchment paper, place the bacon in a single layer on the baking sheet and cook until crispy, 15 to 20 minutes. Transfer the bacon to a paper towel-lined plate to drain. When cool enough to handle, cut the pieces in half. 

Heat a cast-iron skillet over medium-high heat. Spread a thin layer of butter on both sides of each slice of bread. Toast the bread in the skillet until golden brown and crispy, about 2 minutes per side.

In a small bowl, whisk together the mayonnaise and Dijon mustard. Spread 1 tablespoon Dijon mayo on one side of the bread slices. 

To make one sandwich, layer one piece of bread with 2 slices of ham, 1 slice of turkey, 1 slice of cheddar, 4 pieces of bacon, 2 tomato slices, and ¼ of the avocado slices. Season with salt and black pepper. Top with a pinch of greens and another slice of bread, mayo side down.

Repeat step 4 to make the remaining sandwiches. 

Secure each mini sandwich with a toothpick and serve immediately.

Recipe adapted from: Delish