Breakfast Stuffed Portobello Mushrooms With Eggs and Bacon

Imperial September 30, 2026September 30, 2026

Quick Recipe Version (TL;DR)

Yield: 4 servings
Prep Time: 20 minutes
Cook Time: 30 minutes
Total Time: 50 minutes

Quick Ingredients

4 large portobello mushroom caps, 5 to 6 inches wide
1 tablespoon extra-virgin olive oil
1/2 teaspoon kosher salt, divided
1/4 teaspoon freshly ground black pepper, divided
4 slices thick-cut bacon, chopped
5 ounces baby spinach
2 garlic cloves, minced
1 teaspoon fresh thyme leaves
1 tablespoon chopped fresh parsley, plus more for serving
1/8 teaspoon crushed red pepper flakes
3/4 cup shredded low-moisture mozzarella cheese
4 large eggs

Do This

1. Heat the oven to 425°F and line a rimmed baking sheet with parchment paper.
2. Cook the bacon in a skillet for 6 to 8 minutes, then transfer it to a paper towel-lined plate.
3. Clean and season the mushroom caps; roast them gill-side down for 8 minutes.
4. Sauté the garlic and spinach in 1 teaspoon of bacon drippings for 2 to 3 minutes.
5. Combine the spinach with mozzarella, thyme, parsley, red pepper flakes, and half the bacon.
6. Turn over the caps, add the filling, make a center well, and crack one egg into each mushroom. Add the remaining bacon.
7. Roast for 12 to 15 minutes, until the egg whites are set and the yolks are cooked to your liking.

Why You’ll Love This Recipe

Each mushroom is a complete, satisfying breakfast with vegetables, eggs, cheese, and bacon.
Pre-roasting the portobello caps keeps the filling flavorful instead of watery.
The combination of creamy mozzarella, garlicky spinach, and crisp bacon feels indulgent but remains easy to prepare.
It is naturally low in carbohydrates and easy to adapt for vegetarian or spicy variations.

Grocery List

Produce: 4 large portobello mushroom caps, 5 ounces baby spinach, 2 garlic cloves, fresh thyme, and fresh parsley
Dairy: 3/4 cup shredded low-moisture mozzarella cheese
Meat and Eggs: 4 slices thick-cut bacon and 4 large eggs
Pantry: Extra-virgin olive oil, kosher salt, black pepper, and crushed red pepper flakes

Full Ingredients

For the Portobello Caps

4 large portobello mushroom caps, each 5 to 6 inches wide
1 tablespoon extra-virgin olive oil
1/4 teaspoon kosher salt
1/8 teaspoon freshly ground black pepper

For the Spinach and Bacon Filling

4 slices thick-cut bacon, cut crosswise into 1/2-inch pieces
5 ounces baby spinach, roughly chopped if the leaves are large
2 garlic cloves, finely minced
1 teaspoon fresh thyme leaves
1 tablespoon finely chopped fresh parsley
1/8 teaspoon crushed red pepper flakes
3/4 cup shredded low-moisture mozzarella cheese, about 3 ounces
1/8 teaspoon kosher salt
1/8 teaspoon freshly ground black pepper

For the Eggs and Garnish

4 large eggs
1 tablespoon chopped fresh parsley
Freshly ground black pepper, to taste

Breakfast Stuffed Portobello Mushrooms With Eggs and Bacon – Closeup

Step-by-Step Instructions

Step 1: Heat the oven and prepare the pan

Position a rack in the center of the oven and preheat the oven to 425°F. Line a large rimmed baking sheet with parchment paper. Choose a sheet with raised edges because the mushrooms may release some liquid as they roast.

Step 2: Clean and season the mushrooms

Wipe the portobello caps with a slightly damp paper towel to remove any dirt. Avoid soaking them in water, which can make them soggy. Twist out the stems and reserve them for another use, such as an omelet or soup. Using a small spoon, gently scrape away the dark gills to create more room for the filling.

Brush both sides of the caps with the olive oil. Season them evenly with 1/4 teaspoon salt and 1/8 teaspoon black pepper. Arrange the mushrooms gill-side down on the prepared baking sheet.

Step 3: Pre-roast the mushroom caps

Roast the mushrooms gill-side down for 8 minutes. This head start softens the thick caps and encourages excess moisture to drain before the filling is added. Remove the pan from the oven, carefully turn the caps gill-side up, and blot any liquid inside the cavities with a paper towel. Keep the oven set to 425°F.

Step 4: Cook the bacon and spinach

While the mushrooms pre-roast, place the chopped bacon in a large skillet over medium heat. Cook for 6 to 8 minutes, stirring occasionally, until browned and crisp. Transfer the bacon to a paper towel-lined plate with a slotted spoon. Carefully pour off the drippings, leaving 1 teaspoon in the skillet.

Return the skillet to medium-low heat. Add the minced garlic and cook for 30 seconds, stirring constantly. Add the spinach and cook for 2 to 3 minutes, tossing frequently, until completely wilted. Continue cooking for another 30 seconds if liquid remains in the pan. Remove the skillet from the heat and let the spinach cool for 2 minutes.

Step 5: Mix and add the filling

Place the cooked spinach mixture in a medium bowl. Add the mozzarella, thyme, 1 tablespoon parsley, crushed red pepper flakes, remaining 1/8 teaspoon salt, remaining 1/8 teaspoon black pepper, and half of the crisp bacon. Stir until evenly combined.

Divide the mixture among the mushroom caps, arranging it around the outer edge of each cap. Leave a deep, approximately 2-inch-wide well in the center of each mushroom to hold an egg.

Step 6: Add the eggs and remaining bacon

Crack one egg into a small cup or ramekin, then carefully slide it into the well of one mushroom. Repeat with the remaining eggs. Using a cup makes it easier to remove any shell and gives you more control when adding the egg. Sprinkle the remaining bacon around the eggs, keeping the yolks uncovered.

If a mushroom has a slightly smaller cavity, hold back a teaspoon or two of the thin egg white so the filling does not overflow. The yolk and most of the white should fit inside a 5- to 6-inch cap.

Step 7: Roast until the eggs are set

Return the filled mushrooms to the oven and roast at 425°F for 12 to 15 minutes. At 12 minutes, the whites should be nearly set with softer yolks. For firmer yolks, continue roasting for up to 15 minutes. The egg whites should appear opaque with no clear, loose areas remaining. For the highest level of food safety, cook the eggs until the centers reach 160°F.

Step 8: Rest, garnish, and serve

Let the mushrooms rest on the baking sheet for 3 minutes. The eggs will continue to set slightly from the residual heat. Sprinkle with the remaining chopped parsley and add a little freshly ground black pepper. Serve one stuffed mushroom per person while warm.

Pro Tips

Choose wide, deep caps: Portobellos that are 5 to 6 inches across provide enough room for both the spinach filling and a large egg.
Control excess moisture: Pre-roast the caps, drain away released liquid, and cook the spinach until the skillet is dry.
Use low-moisture mozzarella: Fresh mozzarella releases more water and can make the filling loose.
Crack eggs separately: Adding each egg from a ramekin protects the filling from shell fragments and makes it easier to control the amount of egg white.
Watch the final minutes closely: Egg yolks can change from soft to firm quickly, so begin checking after 12 minutes.

Variations

Vegetarian: Omit the bacon. Sauté the garlic and spinach in 2 teaspoons olive oil, and add 1/4 teaspoon smoked paprika for a savory, smoky note.
Mediterranean: Replace half the mozzarella with 1/4 cup crumbled feta and add 2 tablespoons chopped sun-dried tomatoes. Reduce the added salt to account for the feta.
Spicy: Replace the mozzarella with pepper Jack cheese and add 1 tablespoon finely chopped pickled jalapeño to the spinach filling.

Storage & Make-Ahead

These stuffed mushrooms are best served shortly after roasting, while the bacon is crisp and the eggs are freshly cooked. Refrigerate leftovers in a covered container for up to 3 days. Reheat them on a parchment-lined baking sheet in a 350°F oven for 10 to 12 minutes, or until the centers reach 165°F; the yolks will become firmer during reheating. For make-ahead preparation, cook the bacon and spinach filling up to 2 days in advance and refrigerate them separately in airtight containers. Clean the mushrooms up to 1 day ahead, but wait to pre-roast, fill, and add the raw eggs until just before baking.

Nutrition (per serving)