Let’s break down the process into easy-to-follow steps.

Step 1: Preheat and Prepare. Preheat the oven to 375°F (190°C). Line a baking sheet with parchment paper.

Step 2: Prepare Mushrooms. Remove the stems from the mushrooms. You can save the stems for another use (like adding them to soups or sauces), or finely chop them and add them to the breadcrumb filling.

Step 3: Combine Filling Ingredients. In a bowl, combine the breadcrumbs, minced garlic, chopped parsley, nutritional yeast, olive oil, salt, and pepper. Mix well until all the ingredients are evenly distributed.

Step 4: Stuff Mushrooms. Spoon the breadcrumb mixture into the mushroom caps, pressing down lightly to pack it in.

Step 5: Bake. Place the stuffed mushrooms on the prepared baking sheet. Bake for 20-25 minutes, or until the mushrooms are tender and the stuffing is golden brown.

Step 6: Serve. Serve warm, optionally garnished with extra chopped parsley.

These instructions are very easy to follow.