I’m not in Monsey often, but one Sunday afternoon, my family and I passed through. It was a hot day and I really wanted iced coffee, so I headed to Hava Java. It was my first time there, and as I waited for my Skinny Frappe, I watched all the hot, tempting dishes emerge fast out of the kitchen. One dish that caught my attention was the towering Portobello Mushroom Sliders. I wished I hadn’t already eaten lunch! No prob. I went home and recreated the dish, and it was just as good as it looked. Watch Victoria make it here.
Add mushroom caps to a zip-top bag. Add red wine vinegar, garlic powder, basil, and salt. Seal.
Marinate for one hour or up to overnight in the refrigerator.
Preheat oven to 400 degrees Fahrenheit.
Place mushrooms and marinade into a baking pan; bake for 25 minutes.
Add red pepper to the oven (on its own or in a baking pan). Roast until skin is blistered, about 35–40 minutes. Let cool, peel, discard peel and seeds; slice pepper. Set aside.
Prepare the onion: Coat a sauté pan with nonstick cooking spray; heat over medium-high heat. Add sliced onion; lower heat and sprinkle with salt. Cover; cook, stirring occasionally, until onions are golden, about 15 minutes. Set aside.
Coat the sauté pan again with nonstick cooking spray; heat over medium-high heat. Add diced onion; lower heat and sprinkle with salt. Cover; cook, stirring occasionally, until onions are soft, about five minutes. Add spinach; cook an additional two minutes. Season with salt.
Top each mushroom with half the spinach mixture, half the peppers, and half the onions.
Top with one slice of cheese; bake until cheese is golden and bubbling, about 10 minutes.