Start by making the burgers. In a medium bowl, mix ground beef with salt and pepper.
Make 8 medium sized burgers, about 2 oz. each.
You can cook your burgers however you'd like. I grilled them in a large pan for about 3 minutes on each side.
Once the burgers are cooked to your liking, let them rest.
In the same pan, grill the slices of onion for about 2 minutes per side, set aside.
Next, make the copy-cat spread. In a small bowl, add the mayo, ketchup, dill relish, and vinegar. Mix well.
Next, assemble the salad. Start by rinsing and chopping the romaine lettuce.
Add the lettuce to large salad bowls.
To the lettuce, add the tomato slices, grilled onion, burgers and drizzle the spread over the entire thing. Optional, add ketchup.