Balsamic Portobello Mushroom Sandwich

This satisfying portobello sandwich features marinated and roasted mushrooms, a romesco-inspired red pepper spread, and fresh arugula.

Portobello mushrooms are an absolute superstar of the plant ingredient world. Their toothsome texture, and savory but not overpowering flavor, makes their presence welcome in countless meals where you want to create a “meaty” vibe.

Enter these portobello mushroom sandwiches with romesco-inspired roasted red pepper spread and crunchy arugula. This is not your basic vegan veggie sandwich that, let’s face it, can often feel like rabbit food. Instead, it’s a satisfying, savory and multi-textured option you can pack for lunch and picnics, and fully meal prep, too.

Quick Recipe Summary

• What: A veggie sandwich with marinated and roasted portobello mushrooms, romesco-inspired roasted red pepper spread (with chickpeas for protein), and fresh arugula.
• Why You’ll Love It: The savory and lightly sweet portobellos are complemented perfectly by the zingy red pepper spread, creating a hearty sandwich that satisfies with every bite.
• How: Whole portobello mushroom caps are first marinated in a garlicky soy-balsamic mix, then roasted. While the oven’s doing its thing, you blitz up jarred roasted red peppers, almonds, chickpeas, and seasonings into a chunky spread in the food processor.

Key Ingredients + Substitutions

• Portobello Mushrooms: Their hefty size and meaty texture makes them ideal for vegan sandwiches. Look for firm, dry caps with no sliminess.
• The Marinade: The combo of soy sauce, balsamic vinegar, maple syrup, and garlic results in mushrooms that are savory, a bit sweet, and tangy.
• Jarred Roasted Red Peppers: The base of this vibrant sandwich spread. Be sure to drain them thoroughly before puréeing.
• Roasted Almonds: Add richness and nuttiness to the spread. Can be substituted with roasted walnuts. Be sure to use unsalted nuts.
• Chickpeas: Add a bit of protein, extra fiber, and density to the spread.
• Arugula: Its peppery personality complements the other ingredients perfectly. I don’t recommend subbing in other types of greens here.
• Bread: Choose whole wheat for the extra fiber and protein.

Prepping Portobello Mushrooms for Roasting

• Wipe the caps. Washing portobellos directly under the tap may result in the mushrooms absorbing water and therefore turning out gummy. Thoroughly wipe the caps with a damp paper towel instead.
• Scrape out the gills. That’s the dark brown stripey bits on the underside of the mushrooms. While they’re technically edible, they turn out mushy and unpleasant when cooked, so be sure to scrape them off with the edge of a spoon before marinating.

How to Make Portobello Mushroom Sandwiches (Step-by-Step Photos)

Find complete instructions with ingredient amounts in the recipe card below.

Step 1: Prep the Mushrooms

Wipe the caps down with a damp paper towel and trim off the stems. Using the edge of a tablespoon, scrape out the dark brown gills on the underside of the mushrooms and discard.

Step 2: Marinate the Mushrooms

In a large shallow dish (like a baking/casserole pan), mix up the balsamic, soy sauce, maple syrup, garlic, and olive oil. Then thoroughly coat each mushroom in the mixture; really get in there with your hands and massage them all over. Set aside for 10 minutes.

Step 3: Roast the Mushrooms

Transfer to a parchment-covered baking sheet, and roast until the mushrooms are slightly shriveled up and tender, about 25 minutes.

Step 4: Make the Red Pepper Spread

Meanwhile, in a food processor, combine the roasted red peppers, almonds, chickpeas, olive oil, balsamic, and seasonings. Pulse until everything comes together but the spread still has a slightly chunky texture.

Step 5: Assemble the Sandwiches

Slice the mushrooms into chunky slices and toast your bread. Spread the red pepper mixture across the bread, and pile the mushrooms and arugula on top.

Make-Ahead + Serving Notes

These sandwiches are perfect for meal prep: you can roast and slice up the mushrooms, and keep them in an airtight container in the fridge for up to 4 days. The red pepper spread will keep for that long as well, so you can prep both elements in advance and assemble sandwiches throughout the week.

The sandwiches can be served warm or at room temperature. I do recommend warming the mushrooms, if possible, right before assembling your sandwich.

FAQs

More Vegan Sandwich Recipes

• Tofu-Mushroom Banh Mi
• Roasted Eggplant Sandwich with Romesco
• Tempeh Banh Mi with Quick-Pickled Veg
• Tempeh Reuben

Let me know if you try this recipe! Give it a rating below and leave a comment, and don’t forget to tag your creation with @thenewbaguette on Instagram.

The Full Recipe