Melt butter in a pan, optionally add olive oil
Season the butter
Add onions and cook until desired doneness
Add ground beef to the pan and season
Add onion soup mix to the onion-beef mixture
Add 2-3 ounces of water to the mixture
Place the meat mixture on the bread
Top with cheese
Optionally add Dijon mustard or other vegetables
Toast the sliders in the oven or air fryer for about 5 minutes
