1. Make the secret sauce: In a small bowl, mix mayonnaise, ketchup, mustard, relish, garlic powder, and smoked paprika. Chill until ready to use.
2. Caramelize onions: In a skillet over medium-low heat, warm olive oil. Add onions and cook 15–20 minutes, stirring occasionally, until golden brown and sweet. Remove and set aside.
3. Form patties: Divide ground beef into 4 equal portions. Shape into thin patties slightly larger than your bread slices. Season both sides with salt and pepper.
4. Cook patties: In the same skillet over medium-high heat, cook patties 3–4 minutes per side for medium. During the last minute of cooking, top each patty with 2 slices of Swiss cheese and let melt.
5. Butter the bread: Spread one side of each rye slice with softened butter.
6. Assemble & grill: On the unbuttered side of 4 bread slices, spread a layer of secret sauce. Layer with a cheesy patty, caramelized onions, then another sauce-spread slice (buttered side out).
7. Grill sandwiches: Place assembled melts in the skillet over medium heat. Cook 3–4 minutes per side, pressing gently, until bread is golden and crisp, and cheese is oozing.
8. Slice in half and serve immediately with pickles or coleslaw!

✨ The “secret” is in the tangy, smoky sauce—it elevates every bite!

💡 Pro tip: Use a panini press or foil-wrapped brick to get that perfect diner crunch.

PREP TIME & NUTRITION :
Prep Time : 20 mins , Cook Time : 25 mins , Total Time : 45 mins , Servings : 4 sandwiches , Calories : 580 , Net Carbs: 28g , Fats: 32g , Protein: 38g