When I was catering, sliders were one of my go-to menus for casual (and sometimes fancy) parties. They are easy to prep, can be made ahead of time (for the most part) and everyone loves sliders. I’ve made countless versions over the years – bacon, tomato & avocado, and blue cheese & caramelized onion were some of our favorites. 
This year I made one of Mike’s favorite BBQ sandwiches into a slider. The sandwich, a Z-Man is from Oklahoma Joe’s here in KC. They are world famous, and just up the street from our house… too bad the line is always out the door and around the corner. Always. A Z-Man is beef brisket topped with an onion ring, melted cheese, pickles and their BBQ sauce. It is my favorite, too, but I get mine with pulled pork instead of brisket.
My helping hands : ) I made a spread of guacamole, sliders and watermelon tomato skewers.
In addition to the BBQ sliders, I made a classic cheese burger topped with cheddar jack, pickles and a mixture of ketchup and mayo.
Sliders
makes 15 medium sliders 2 pounds of ground beef 1 tablespoon of sea salt 1/2 tablespoon of black pepper 1 tablespoon of dijon mustard 1 tablespoon of steak sauce or ketchup 1 egg 15 mini buns …… monterrey jack cheddar jack ketchup mayo pickles BBQ sauce In a mixer with paddle, combine beef, salt, pepper, mustard, steak sauce and egg. Form 15 patties and place them on a baking sheet. Place in the oven under a high broiler for 5-7 minutes. Remove and place the patties on buns on a clean baking sheet. Cover with foil. Keep them warm in a 250 degrees oven for up to 30 minutes.
I used to mix this together with a fork or my hands, but I have found that the mixer does a great job of mixing and keeping the mixture light.
I scoop with a 2 ounce scoop to make portions easy. 
Meanwhile, go ahead and bake the onion rings according to package.
Form the patties – they should be flatter and bigger than you think. They will shrink down when they cook.
My broiler is set to about 450 degrees.
After just about 5 minutes they are cooked.
I topped half with cheddar jack, then ion rings on the other.
Put slices of Monterrey Jack on the onion rings.
After a minute or two the cheese is melted.
I used yeast rolls from our bakery and made them more hamburger looking by adding sesame seeds.
I brushed a little water on first to get the seeds to stick.
Classic Cheese Burger : Mix of 1/2 ketchup and 1/2 mayo & pickles on Cheddar Jack slider.
For the BBQ burger : BBQ sauce & pickles on the onion ring with melted cheese.
And, of course I used these small bamboo pics to hold everything together.