In a bowl, combine all Burger Patties ingredients and gently mix. Form into 4 patties.
Prepare the Blue Cheese Sauce: In a separate bowl, combine all Blue Cheese Sauce ingredients and mix well. Set aside.
Heat a grill or skillet over medium-high heat.
Cook the burger patties for 4-5 minutes per side, or until cooked to desired doneness. During the last minute of cooking, place a slice of cheddar cheese on each patty to melt.
Toast the hamburger buns lightly.
Assemble the burgers: Spread a generous amount of Blue Cheese Sauce on the bottom bun. Add lettuce, the cheeseburger patty, red onion slices, and top with the top bun. Serve immediately.
