For Mushrooms:

• 7 ounces maitake mushrooms, trimmed
• 1 medium yellow onion, sliced into 1/2-inch slices (about 1 1/2 cups)
• 4 cloves garlic, smashed
• 2 tablespoons olive oil
• 1/2 teaspoon kosher salt
• 1/4 teaspoon freshly cracked black pepper

For Pesto:

• 1/4 cup pine nuts
• 4 cups (packed) kale leaves, roughly chopped
• 4 cloves garlic, roughly chopped
• 1 teaspoon kosher salt
• pinch red pepper flakes
• 1 tablespoon nutritional yeast
• 1/3 cup extra virgin olive oil
• 12 ounces dried fettuccine