---
title: Prep & Bake Golden Mozzarella Portobello Sandwiches
source:
  name: HelloFresh
  url: https://www.hellofresh.com/recipes/golden-mozzarella-portobello-sandwiches-69026481f01aaa49dd03c593
servings: 2
prep_time: 15 minutes
cook_time: 15 minutes
time_required: 30 minutes
difficulty: Easy
allergens:
  - Wheat
  - Milk
  - Eggs
tags:
  - Veggie
  - Easy Prep
rating: 4.0
rating_count: 309
source_chef: Courtney Laga
review_highlights:
  - theme: Flavor
    text: Savory, earthy mushrooms and smoky mustard sauce
  - theme: Ease of prep
    text: Easy to make, though assembly can be messy
image: "https://images.recipes.furrysalamander.com/prep-bake-golden-mozzarella-portobello-sandwiches.avif"
---

Preheat oven to 425°F. Wash and dry all produce.

Drizzle both sides of each @portobello mushrooms{2%large} with @olive oil{2%tsp}; rub to evenly coat. Season all over with half the @fry seasoning{1%unit}, @salt{½%tsp}, and @black pepper{¼%tsp}. Place mushrooms, top sides down, in @oven-ready tray{1%unit}. Evenly sprinkle mushrooms with @mozzarella cheese{¾%cup}.

Evenly sprinkle @panko breadcrumbs{½%cup} over mushrooms, lightly pressing to adhere. Tightly cover tray with aluminum foil. Bake on top rack until mushrooms are tender ~{15%minutes}.

While mushrooms bake, in a #small bowl{}, combine @mayonnaise{2%tbsp} and @smoky mustard{2%tbsp}.

Toss @mixed greens{1%cup} with @buttermilk ranch dressing{2%tbsp}. Slice @brioche buns{2%units} in half horizontally and @tomato{1%unit}. Spread cut sides of buns with smoky mustard sauce; fill buns with tomato slices, mushrooms, and @crispy fried onions{2%tbsp}. Serve with dressed greens on the side.