Prep all ingredients per instructions above.
Mix together the ground beef, steak seasoning, and Worcestershire sauce. Form into even patties. Transfer to a plate, cover with plastic wrap, and reserve in the fridge until you are ready to cook (see note).
Preheat the air fryer to 400°F (200°C) for the fries and preheat the grill or grill pan on medium heat for the mushrooms and hamburgers.
Brush the mushroom caps with olive oil.
Grill the mushrooms over medium heat for about 4-5 minutes per side or until they are tender. Set them aside. Chop or slice.
Prepare the air fryer fries: Pat the potato strips dry with a towel or paper towel. In a bowl, toss the potato strips with olive oil, salt, pepper, and any desired seasonings. Place the seasoned potatoes in the preheated air fryer and cook for about 15-20 minutes, shaking or flipping them halfway through, until they are golden brown and crispy.
Cook the burger patties: Add the patties to the grill and cook on both sides, getting a nice crusty char to the desired doneness (see note) using a thermometer. When the burger is 3/4 of the way cooked to your liking, add the cheese and cook until melted.
Make the lemon sparkling water: Fill two glasses with sparkling water. Squeeze some fresh lemon juice into each glass. Garnish with lemon slices and serve with ice if desired.
Assemble and serve: Toast the hamburger buns on the grill or in a toaster. Layer the bun with burger and mushrooms. Add lettuce, tomato, and onion if desired. Serve the burgers with a side of air fryer fries and sparkling water.