48 medium (2-pounds) white mushrooms
1 package (10-ounces) frozen chopped spinach, thawed
4 ounces feta cheese, crumbled
2 ounces cream cheese, softened
½ cup finely chopped green onions
½ cup freshly grated Parmesan cheese
Preheat oven to 350°F. Using damp paper towels, wipe mushroom caps clean; remove and discard stems, or save for another use. In colander, squeeze liquid out of spinach until dry.
In large bowl, mix spinach, feta, cream cheese, green onions, and ¼ teaspoon salt until well combined. Fill each mushroom with heaping teaspoon spinach mixture; top with Parmesan.
Transfer to 15 ½-inch by 10 ½-inch jelly-roll pan; bake 20 minutes or until mushrooms are tender and filling is golden brown.