Portobello Layered Mashed Potatoes

I adapted this from the recipe I found on Cooking Light and it was DELICIOUS. A great twist on mashed potatoes. I'd bet you can even skip the baking step and just stir the mushroom mixture into the mashed potatoes. Its a shame you can't see the layers of potatoes and mushrooms in my pic though.
1 1/2 pounds Yukon gold potatoes, peeled and quartered
1/3 cup half and half
2 tablespoons grated Parmesan cheese, divided
1/4 teaspoon salt
1/8 teaspoon black pepper
1/2 tablespoon light butter
1/4 cup fresh onion, finely chopped
2 garlic cloves, minced
1 1/2 cups finely chopped portobello mushroom caps
1 tablespoon dried basil, divided
non-stick cooking spray
1/4 teaspoon olive oil

Place potatoes in a saucepan, and cover with water; bring to a boil. Reduce heat, and simmer until tender; drain, reserving 1/4 cup cooking liquid. Add potatoes back to pot; mash. Add reserved cooking liquid, half and half, 1 tablespoon grated Parmesan, salt, and pepper, and mix until well blended.

Melt butter in a medium nonstick skillet over medium-high heat. Add onion and garlic, and sauté 2 minutes. Add mushrooms and cook 2 minutes, without stirring. Cook until liquid almost evaporates (about 4 minutes), stirring frequently. Remove from heat, and stir in half the basil.

Preheat oven to 375°.

Spread one-third of potato mixture in bottom of a 1.5-quart casserole dish coated with cooking spray. Spread half of the mushroom mixture over potato mixture; repeat layers, ending with potato mixture. Sprinkle top with remaining cheese and basil; drizzle with oil. Bake for 25 minutes.

Yield 5 servings (serving size: 1 cup)

WW info:
flex: 3 points
core: 1 point