Brown meat in a large skillet over medium heat. Then remove it from the heat and drain off the fat. Add ketchup, mustards and barbecue sauce to the meat and stir to combine. Taste and add more of whatever you think it needs. Keep warm.
Cut hamburger buns into 1-inch cubes. Melt 1/4 stick of butter in a separate skillet over low heat, then add the bread cubes and toss to coat. Toast the croutons in the skillet over low heat for about 10 -12 minutes, adding 1/4 stick of butter every couple of minutes until you've used the whole stick. (This will ensure all the croutons soak up the butter and toast nicely.)
To assemble each salad, pile torn lettuce on a plate. Pile on a good quantity of the meat mixture, then top with plenty of grated cheddar. Add diced tomato, chunks of pickles and slices of red onion over the top. Then sprinkle warm croutons all around the plate.