In the world of comfort food, the cheeseburger reigns supreme.  It’s great all year long and fantastic for lunch or dinner. With this recipe and a few helpful tips, you'll be on the road to the ultimate burger at home. 

INSTRUCTIONS:

1. 1. In a bowl, combine ground chuck and ground sirloin and mix together. Divide the beef into 4 equal portions and shape into patties, about 1 inch thick. Place a thumbprint in the center of each patty, about 1/2 inch thick to help stop the burgers shrinking. Season both sides with salt and pepper, cover with cling wrap, and place in the refrigerator for 30 minutes.
   2. Preheat the oven to 350 degrees.
   3. Heat a griddle or pan over medium. When hot, melt one tablespoon of butter on the griddle and add the sliced onions. Season the onions with salt and give them a toss to get the coated in the butter. Cook, turning every minute, for 15 - 20 minutes until nicely caramelized. Set aside.
   4. Melt one tablespoon of butter on your griddle attachment. Place your burger patties on the hot griddle, and insert 3 or 4 knife cuts into each burger. This will help the burgers cook through evenly. Fry for 4 minutes, then flip and cook an additional 4 minutes. Place 2 slices of American cheese on each burger patty, and transfer to the preheated oven to melt. (About 5 minutes).
   5. While the burgers are frying, make the sauce. In a blender, combine mayo, mustard, relish, and ketchup, and pulse until smooth. (This can be done ahead of time, and kept in the refrigerator until you're ready to build the burgers)
   6. Build the burgers with 1 tablespoon of burger sauce, a patty, 2 tablespoons of grilled onions, tomato, and lettuce. Spoon one more tablespoon of sauce on the top bun and serve immediately.

CRANK UP YOUR COOKING TIP:

Caramelize the onions and fry the burger patties on the versatile griddle attachment that can be used with PowerPlus® 2-in-1 Burner & Griddle on the Frigidaire Professional Range