Well, I'm back at it again with a not-really-a-burger burger. Last time it was salmon and now I'm using the same word for a giant mushroom cap as a glorious, beefy patty. For a true burger lover, this is getting embarrassing. But once again, I must admit I was pleasantly surprised.
The recipe I used, adapted from Everyday Food, roasts the caps covered in a hot oven to concentrate their flavor and keep them tender (a trip to the grill, where a lot of mushroom burgers probably get cooked as consolation for the vegetarians, probably isn't the best route to juiciness). If this were my only knowledge of hamburgers, it would be a tragedy; but it was quite welcome as something a little different.
The other smart move in this recipe is the topping, which is an avocado-based spread. The recipe called for using horseradish and mustard mashed into the avocado, but I skipped them both in favor of minced shallots and lemon juice. Either way, the avocado was wonderful against the (yes, I'll say it) meaty mushroom. A tender bun that's easily bitten through is essential, because the mushroom has a tendency to slip out.
- 4 large portobello mushrooms, stems removed
- 1 tablespoon olive oil
- Coarse salt and ground pepper
- 1 ripe avocado, pitted, peeled, roughly chopped
- 1 medium shallot, peeled and minced
- 1 tablespoon fresh lemon juice
- 4 soft rolls, split horizontally
- 1 beefsteak tomato, cored and thinly sliced
Preheat oven to 425 degrees. In a roasting pan or rimmed baking sheet, toss mushrooms with oil, 1/2 cup water, and a pinch of salt and pepper. Arrange stem-side down and cover loosely with foil to allow some steam to escape. Roast for 30-45 minutes, until the mushrooms are tender.
When the mushrooms are nearly done, combine the avocado, shallot, lime juice, and a pinch of salt and pepper in a bowl. Mash thoroughly into a paste.
Toast rolls, and place mushroom on bottom half. Top with avocado mixture and tomato.