Creamy Spinach Mushroom Lasagna - With greens

1 lb penne pasta 1 tablespoon olive oil 1 cup red onion , diced 2 garlic cloves , minced 8 ounces baby portabella mushrooms , sliced 1 1/2 cups frozen chopped[...]

itemscope itemtype="http://data-vocabulary.org/RecipeIngredient"> 1 teaspoon garlic powder 1 (10-ounce) can condensed reduced-fat cream of chicken soup,[...]

7 tablespoons butter , divided 16 ounces sliced mushrooms 1/2 cup chopped green onion 1/4 cup minced shallot 3 cloves garlic , minced 16 ounces frozen chopped[...]