Step 1

Blend Sirloin chuck, brisket, and short rib ground beef mixes, then mix with some egg. I suggest you prepare this a day before grilling. Patty into 8 oz patties and then refrigerator for 24 hours before using; this will help the patties stay together and won't come apart as you are grilling them.

Step 2

Make sure the grill is scorching before putting the patties on the grill. Now season the patties with salt and pepper and add a little oil. Make sure to roll the sides of the patties so they get fully seasoned.

Step 3

Make sure burgers are at room temperature 10 minutes before grilling them. Look for the hottest part on the grill and place the burger patties down on the grill. The real secret is to move the patties as little as possible once you place the burger patties on the grill.

Step 4

Beginning preparing the hamburger buns as the burgers are cooking. Season buns with salt and pepper, and crisp them on both sides on the grill.

Step 5

Season the thick-sliced onions with salt and pepper, add some oil and place onions on the grill as the buns and burgers are cooking.

Step 6

Now start basting your patties by brushing them on each side just about two minutes before taking off the grill to add some more flavor. Grill each burger patties for 3 1/2 to 4 minutes on both sides.

Step 7

Thirty seconds before the patties come off the grill; you need to season the patties again, then add your jack cheese on top to melt while the burgers are still on the grill.

Step 8

Setup the Brioche buns; add the mustard mayo blend, lettuce, and tomatoes before taking the burger patties off the grill. First, you start by placing a tablespoon full of mustard mayo blend on both sides of the top and bottom of the bun. Then gently fold the lettuce to fit onto the bun and press down on the lettuce, ensuring it stays folded.

Step 9

After the mustard mayo blend and lettuce, add a thick slice of tomato to the lettuce, season the tomato with salt and pepper, and dab more mayo on top.

Step 10

Add the burgers on each of the Pre-made dressed Brioche buns. Place grilled onions on top of each patty finish by placing the top bun.