Preheat the oven to 425°F (220°C).

Cube the potatoes, toss with olive oil, salt, and pepper, then spread on a baking sheet. Roast for 40 minutes, flipping halfway.

In a skillet, sauté the onion in olive oil until soft. Add ground beef and cook until browned, seasoning with spices before removing from heat.

Whisk together mayonnaise, chopped gherkins, ketchup, and Dijon mustard until smooth. Let sit to meld flavors.

Assemble bowls with lettuce, roasted potatoes, beef, cheese, tomatoes, onion, and drizzle sauce on top.