Skinnytaste's Sausage Zucchini Boats

From skinnytaste.com

1 1/4 c. marinara
4 medium zucchini
1 tsp. oil
1/2 small onion, finely diced
3 cloves garlic, crushed
14 oz. Italian sausage, removed from casing
1/2 c. shredded mozzarella
8 tsp. grated parmesan

Bring a large pot of water to a boil.  Preheat oven to 400.  Cut zucchini in half lengthwise and scoop out flesh.  Chop flesh into small pieces and set aside.  Drop zucchini halves in boiling water and cook for 1 minutes.  Remove from water.  Layer 1/2 cup marinara at the bottom of a 9 x 13 baking dish and place zucchini halves in cut side up.  Brown sausage.  Heat oil and add onion and garlic.  Cook 2-3 minutes until onions are translucent.  Add chopped zucchini, season with salt and pepper, and cook 2-3 minutes.  Combine with sausage and cook a few more minutes.  Fill each zucchini with 1/3 cup sausage and top with 2 tablespoons sauce, 1 tablespoon mozzarella, and 1 teaspoon parmesan.  Cover with foil and back at 400 for 35 minutes.