✦ Step-by-Step Instructions
5 StepsClean and Prepare Portobello Caps
Preheat your oven to 400°F (204°C). Wipe portobello caps clean with a damp paper towel. Twist off stems and discard. Using a teaspoon, gently scrape out the dark gills from inside each cap to create a deep stuffing cavity. Brush both sides of the caps with olive oil and place gill-side up on a parchment-lined baking sheet.
Mix Savory Slider & Cheese Filling
In a medium mixing bowl, combine 6 crumbled White Castle sliders, 4 ounces softened cream cheese, 0.25 cup grated parmesan, minced garlic, Worcestershire sauce, and red pepper flakes. Mix with a fork until thoroughly incorporated into a thick, savory stuffing.
Mound Stuffing into Mushroom Caps
Divide the slider filling evenly among the 6 prepared mushroom caps, mounding slightly in the center. Sprinkle the remaining 0.25 cup parmesan cheese over the top of each cap.
Bake Until Golden and Bubbling
Bake at 400°F (204°C) for 18 to 20 minutes until the mushroom caps are fork-tender and the parmesan cheese crust is bubbly and golden brown.
Garnish and Serve
Remove from the oven, let rest for 3 minutes, then garnish with fresh parsley and an optional light drizzle of aged balsamic glaze reduction. Serve warm with steak knives and forks.
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Craver Test Kitchen Secrets
- ✦ Wipe mushroom caps clean with a damp paper towel instead of rinsing; wet mushrooms create a soggy filling.
- ✦ Leave the slider bun crumbs mixed into the cream cheese filling; the bread crumbs soak up mushroom juices and create a luxurious stuffing texture.
- ✦ Assemble up to 24 hours in advance and keep refrigerated until ready to bake.
Recipe FAQs & Home Cooking Tips
Can you make White Castle stuffed mushrooms in an air fryer? ▼
Yes, you can air fry stuffed portobello mushrooms at 375°F (190°C) for 10 to 12 minutes until the cheese is bubbling and the mushroom is fork-tender.
Are White Castle stuffed portobello mushrooms gluten-free? ▼
No, standard White Castle slider buns contain wheat gluten, but you can prepare a gluten-free variation by discarding the buns and using only the steam-grilled beef patties mixed with cream cheese and parmesan.
Can I prepare these stuffed portobello caps ahead of time? ▼
Yes, assemble the stuffed caps up to 24 hours in advance, cover tightly with plastic wrap in the refrigerator, and bake straight from the fridge adding 3 extra minutes to the bake time.
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