It’s “open” so that you can pile tons of freshly grilled mushrooms and onions on a double cheeseburger without overloading in bread.
- 1lb lean ground beef
- Shredded Swiss cheese
- Yellow onion, sliced
- Mushrooms, cremini or white, sliced.
- Baby spinach, hand torn removing stems.
- Bun: English muffin, brioche or plain hamburger bun.
Allow 20-30 minutes to reduce onions in 1 tbsp olive oil at medium heat, seasoned with salt and pepper. After 15 minutes, add mushrooms and 2 tbsp water. Toss frequently. Set aside in a covered bowl to stay warm. Keep pan for burgers.
Roll hamburger into 1/3 lb balls and season with salt and pepper. Flatten into 1/2″ patties and sauté in pan from onions and mushrooms, 6 minutes per side until 135F.
Set 2 patties on 1 half of toasted bun each, adding 1/4 cup shredded cheese (or more – seriously, add more).
Add torn baby spinach, without stems.
Cover both patties with mounds upon mounds of onions and mushrooms.
No additional condiments are required, but don’t hesitate to experiment with:
- Roasted bell peppers
- Pepperoncini or banana peppers
- Dijon mustard
- Roasted cherry tomatoes
- Dill pickles and sriracha (you need to try this!)