On a baking sheet, toss the fries with the melted butter and rosemary, then spread them out in an even layer. Bake according to the package directions (usually 25 to 28 minutes at 425°F).
Meanwhile, prepare a grill or grill pan to medium-high heat.
Form the beef into 4 patties. Drizzle the patties with the oil, then sprinkle with the steak seasoning and cook to your desired doneness, about 4 minutes per side for medium. Add a cheese slice to each patty in the final couple of minutes of cooking, cover, and allow to melt.
Divide the fries between 4 bowls and top each with a cheeseburger, some lettuce, tomato, pickles, and jalapeños. Drizzle with ketchup, mustard, and/or with burger sauce.
