Place the bacon in a single layer on a baking sheet and bake in the oven until crispy, about 15 minutes.
In a large bowl, combine the beef with the red onions, cilantro and seasoning salt.
Mix until just combined. Divide the mixture to form 4 patties.
Sprinkle each patty with salt and pepper.
Heat a grill or grill pan over high heat and grill the burgers to medium-well, about 5 minutes on each side. Top the burgers with 1 slice each of Cheddar and pepper Jack.
Transfer the burgers to buns and top each with 2 slices of bacon, 3 pickles, a lettuce leaf and a tomato slice.