80% lean, quality ground beef or bison. No mixing in Lipton soup mix or breadcrumbs or onions or anything. You're having a hamburger, not meatloaf. I put a little bit of olive oil on the outside of the patty just so the seasoning will adhere and then I'll season it with just salt & pepper. Sometimes garlic salt, but that's it. Then grilled over high heat on my charcoal grill. I always put cheese on my burger, generally either cheddar or pepper-jack, but sometimes swiss.

I actually just got done eating a burger that I cooked in my sous-vide machine. Vacuum sealed in a bag with just salt & pepper, then cooked in the water oven at 130° for 2+ hours. Then I unpacked it and seared it in a cast iron skillet for about a minute per side. I only cooked it this way because I have these frozen patties that are enormous and they fall apart if you let them thaw out. They're 9.5oz. American Wagyu patties. With this technique I can vacuum seal them while they're still frozen so the patty stays together. It's an odd way of cooking hamburger though. The meat inside stays perfectly medium-rare all the way through except for the seared part outside.