They were initially inspired by thoughts of a big portobello mushroom burger I make that got heavily influenced by a photo I spied in a magazine (of pulled pork sliders) and what I believed a mushroom could transform to. It's a long story.
At any rate, I discovered that while it's fun to slice portobellos into thin strips, sauté them with lots of good flavor and pile them high atop a mini bun... it's more fun (and wise) to use what you have to its full advantage. Portobellos, by their very nature, are perfect vessels for piling on flavorful fixings. And, getting the right size mushroom is the only requirement to making it work in slider form.
Once wiped clean, stemmed and gilled, portobellos (or large cremini mushrooms) are only too happy to turn on their heads to welcome fixings in the bellies that nature bestowed them. And... as such... the piling on is more apt to stay put.
And so... after several flavorful trials at getting a satisfying little mushroom-based veggie slider to the table (in well under nine attempts... but, yes, more than one), this one truly delivered.
First, a little mingle of sautéed onion, fennel and roasted red pepper get cradled in the belly of a lightly seared portobello, then capped with a few golden-tinged slices of zucchini and a generous cut of fresh tomato. A little topping of mild white cheddar and a few minutes under the broiler sets all this in place. Then a fluff of baby greens and a good schmear of a marinated artichoke spread are added to finish it off. All this nestled in (and on) the belly of a flavorful portobello!
You can really pile on just about anything that appeals to you. Mushrooms are pretty welcoming little creatures... they kind of take on the life you give them.
Portobello Mushroom-Veggie Sliders with a Marinated Artichoke Spread
makes 4 sliders
2 to 3 tablespoons extra virgin olive oil
1 medium onion, quartered, thinly sliced (about 1 1/2 cups sliced)
1 medium bulb fennel, trimmed (fronds discarded), quartered, cored, thinly sliced (about 1 cup sliced)
4 oz. roasted red pepper (half an 8 oz. jar), drained and diced
1/4 teaspoon kosher salt, more to taste
1/4 teaspoon ground black pepper, more to taste
2 medium zucchini, trimmed and cut into 3/8" slices, on diagonal (to get a bit of a larger surface area)
4 portobello mushrooms (approx. 3" diameter, or large cremini mushrooms), stems and gills removed
2 tomatoes, cut into thick (3/8" to 1/4") slices
4 slices mild white cheddar cheese
mixed baby greens to top
4 slider buns (used Challah slider buns here)
1 6.5 ounce jar marinated artichoke hearts, drained
2 tablespoons vegenaise (or favorite mayo)
Preheat oven broiler. Place marinated artichoke hearts and vegenaise in bowl of food processor. Pulse approximately 12 times; stop processor and remove top to scrape sides of bowl; replace top to processor bowl and pulse again 5 or 6 times (each pulse is about 1-2 seconds), until smooth (it's okay to have it not be entirely puréed). Transfer spread to small bowl and set aside.
Heat a little more than 1 tablespoon olive oil in a skillet over moderate heat, add onion and fennel; sauté lightly for 5 to 8 minutes, until translucent. Add roasted red pepper and sauté for another 3 to 5 minutes. Add just a pinch of salt and pepper. Transfer onion mixture to a plate and set aside. Using the same skillet (do NOT wipe clean), turn heat up to medium and add a bit more olive oil (a little less than a tablespoon) and zucchini (in one layer); season with 1/4 teaspoon salt and 1/4 teaspoon pepper. Let zucchini cook for about 3 to 4 minutes, until golden on one side, then turn to cook for another 2 to 3 minutes. Transfer to plate and set aside. Add remaining olive oil to same skillet (do NOT wipe clean) and place mushrooms (belly down) to cook for about 3 to 5 minutes; turn and cook another 2 to 3 minutes, until just golden. Remove to plate and set aside. Add sliced buns to skillet (yep... no wiping), cut side down, to toast for 2 to 4 minutes. (If skillet size allows, you can sauté mushrooms and toast buns at same time). Arrange bun bottoms on a baking sheet, spread with a teaspoon or so of artichoke mix, and top each with a mushroom (belly up). Fill mushroom with a few tablespoons of onion mix, cover top of onion mix with 3 or 4 slices of zucchini, top with a fresh tomato slice, and cap with a slice of cheese. Place under broiler for 2 to 4 minutes (watch carefully), until cheese has melted. Remove from oven, top with a bit of greens and tops of buns (also spread with artichoke mix). Serve immediately.