Stuffed Roasted Onion with Cheese and Spinach Yield: One serving 1 medium onion 113 gr. cooked and drained spinach 1 cup ricotta cheese 56 gr. grated Parmesan cheese 1 egg yolk Olive oil Parmesan cheese Cherry tomatoes Arugula Balsamic vinegar Salt and pepper to taste Nutmeg to taste Preheat oven to 120ÂºC. In a bowl, combine spinach, ricotta cheese, Parmesan cheese, egg yolk, salt, pepper and nutmeg. In a saucepan, bring water to a boil. Peel outer part of onion and drop into boiling water. Cook 15 minutes. Separate onion sections. Fill each onion section with a small amount of filling. Close sections to make the onion whole. Place onion in a baking pan. Sprinkle olive oil and Parmesan cheese on top. Bake in 120ÂºC oven for 10-15 minutes. To serve: Arrange arugula and cherry tomatoes on a salad plate, sprinkle with olive oil and balsamic vinegar. Place stuffed onion on top.