Spinach Soup with Gruyere

In a large skillet, heat olive over over medium heat. Add spinach and garlic and cook for 2 to 3 minutes, stirring constantly, or until wilted. Add spinach to a blender or food processor. Pour in 1/4 cup hot water and pulse until pureed. Set aside. In a large soup pot, cook onion in butter over medium heat until onions begin to soften. Sprinkle flour over the top and stir to combine. Cook for about 2 minutes, then pour in milk, stirring occasionally. Add salt, pepper, and cayenne and stir to combine. Cook over medium heat for 5 minutes, stirring constantly. Pour in pureed spinach, then cook another 3 to 5 minutes until thickened. Check seasonings, adding more salt, pepper, or cayenne as needed. Serve in a bowl. Add a little grated Gruyere.