Preheat oven to 325°F.
In a large bowl, combine the ground beef, mustard, parsley, and thyme. Season with salt and pepper. Form into 6 patties (thinner at the center for even cooking). In a large skillet, heat the olive oil on medium-high. Place the patties into the skillet and cook, turning once, about 10 minutes or until cooked all the way through. During the last few minutes of cooking, add the Cooper® cheese and cover to melt.
While the patties are cooking, brush the tops of the rolls with water, then sprinkle with kosher salt. Place rolls on a baking sheet and bake until heated through, about 3 minutes. Remove from the oven and split the rolls.
Assemble your sliders:
Divide the patties among the roll bottoms. Add pickles, lettuce, onion, tomato (seasoned with salt and pepper), and mayonnaise. Complete with the roll tops and serve.
*Consuming raw or undercooked meats, poultry, seafood, shellfish, or eggs may increase your risk of foodborne illness.