A friend and I have been cooking together for years. We always make delicious food, but occasionally we out-do ourselves. When we first started cooking together, he shared his methods of making a PTP (Prime Time Patty). Essentially it is just a meatloaf burger, but the deviations make it so much better.
Originally it was just diced onion, garlic, and green pepper mixed with Worcestershire, salt and pepper and ground beef mixed and formed into a patty. From there we have experimented with changes that either get adopted, or sworn to never repeat. Of the adoptions were diced jalapenos and cock sauce.
A little more than a year ago, our recipe for the burger went into two different directions. He started adding ketchup and using ultra lean beef, and I started adding soy sauce. The one thing that he did add that I quickly repeated was adding battered and fried onions and jalapenos to top the burger.
If I had the grilling resolve that he had, I would also grill them over charcoal, but the convenience of propane wins for me. The taste difference is definitely noticeable with all of the sugars of the mixture absorbing all of that delicious, smoky flavor.