Cheesy Portobello "Smash" Burger with Avocado, Sprouts & Romaine Salad

Directions

1. Whisk mayo, ketchup, and spices to make a simple sauce and set it aside.
2. Rinse and dry all fresh produce, keeping greens separate.
3. Heat a nonstick skillet over medium-high heat.
4. Prepare the mushrooms by removing the stems, then brush with oil and season both sides with salt and pepper.
5. When the skillet is hot, place the mushrooms in cap-side down and cook until they begin to soften, about 3 minutes; flip and cook until the bottoms are golden, another 2–3 minutes.
6. In a medium bowl, whisk oil, vinegar, Dijon, honey, and a pinch of salt to create the dressing.
7. Thinly slice the mozzarella.
8. Turn the mushrooms over, lay slices of mozzarella on top, and cook until the cheese melts and the mushrooms are tender, 3–4 minutes more.
9. Chop or tear the romaine; toss with the dressing in a large bowl. Slice one tomato into thin rounds and dice the other; add both to the salad and toss.
10. Halve and pit the avocado, scoop out the flesh, and cut it into thin slices. Arrange on a plate with the tomato and set aside.
11. Toast the buns if desired, then spread the sauce on the bottom halves, add the cheesy mushrooms, top with tomato, avocado, and sprouts, and cap with the top buns; serve with the salad on the side.