Mise en Place – Prep

1. Rehydrate the Sun-Dried Tomatoes – Place the dry-packed sun-dried tomatoes in a small bowl or pan and cover them with hot, not quite boiling, water. Let them soak for about 20-30 minutes, then drain and pat them dry.
2. Fry the Bacon – Instead of cooking whole strips and crumbling them later, cut them into small pieces before frying. This ensures even cooking and crispiness. Fry in a pan over medium heat until crispy, then transfer to a paper towel-lined plate.
3. Toast the Walnuts – In a dry skillet over medium-low heat, toast the walnuts for 2-3 minutes, stirring frequently until fragrant. Remove from heat and let them cool.
4. Chop the Vegetables – Finely chop the green onions and spinach. If using frozen spinach, thaw it completely and squeeze out as much moisture as possible using a paper towel or clean kitchen towel.
5. Prepare the Mushrooms – Gently remove the stems from each baby bella mushroom. Use a damp paper towel or a soft brush to wipe away any dirt—avoid rinsing them with water, as mushrooms can absorb moisture.
6. Shred the Cheeses – Freshly grate both the Parmesan and mozzarella. This helps them melt better and creates a smoother, creamier texture in the final dish.

Making the Sun-Dried Tomato Pesto

1. In a food processor, add the rehydrated sun-dried tomatoes, the toasted walnuts, Parmesan cheese, garlic, olive oil, lemon juice, salt, and pepper, then pulse until finely chopped.
2. If the mixture is too thick, drizzle in a little more olive oil until it reaches your desired consistency.

Preparing the Stuffing Mixture

1. In a mixing bowl, combine the sun-dried tomato pesto, chopped spinach, chopped green onions, crispy bacon pieces, grated Parmesan cheese, and red pepper flakes.
2. Stir everything together and mix until the stuffing is well combined.

Fill the Mushrooms

1. Using a spoon, generously fill each mushroom cap with the prepared stuffing mixture. Press it in gently so it holds together.
2. Sprinkle freshly grated mozzarella on top of each stuffed mushroom.

Bake

1. Preheat your oven to 375°F.
2. Line a baking sheet with parchment paper or spray with non-stick spray.
3. Arrange the stuffed mushrooms on the sheet and bake for 15-20 minutes, or until the mushrooms are tender, the filling is heated through, and the mozzarella is golden and bubbly.

Making the Balsamic Glaze

While the mushrooms are baking, make the balsamic glaze for that final gourmet touch.

1. In a small saucepan over medium heat, combine balsamic vinegar and the honey.
2. Bring to a simmer, then reduce the heat to medium-low and let it reduce until thickened, about 8-10 minutes.
3. Once it reaches a syrupy consistency, remove from the heat and whisk in a small pat of butter. This adds a glossy sheen and smooth finish to the glaze.

Finishing Touches and Serving

1. Once the mushrooms are out of the oven, let them cool for a minute or two.
2. Drizzle the warm balsamic glaze over the stuffed mushrooms for a tangy-sweet contrast to the rich filling.
3. Serve immediately while they’re hot, cheesy, and irresistible.