Kale and Parmesan Baked Pasta Shells

I made this as a quick dinner the other night, adapted from this recipe. It was super tasty, but the other thing I like about it is how versatile it is. Gluten free? Use a rice pasta like this one. Vegetarian? See below main recipe for a sweet Italian sausage substitute.

Ingredients

3/4 

pound 

pasta shells

2 

tablespoons 

olive oil

1/2 

pound 

sweet Italian sausage, casings removed*

1 

bunch kale, stems discarded and leaves torn

One 

14.5-ounce 

can diced tomatoes, NOT DRAINED

2/3 

cup 

heavy cream

4 

ounces 

Asiago or fontina, grated (1 cup)

2 

ounces 

Parmesan, grated (1/2 cup), plus more for serving

Kosher salt and black pepper

Directions

1. Heat oven to 450° F. Cook the pasta for 3 minutes less than the package directions specify. Take out 1/3 cup of pasta water and set aside. Drain the pasta and return it to the pot. (I used a large dutch oven to cook the pasta and then baked the casserole in it as well.
2. Meanwhile, heat the oil in a large skillet over medium-high heat. Cook the sausage, breaking it into large pieces, until browned, 4 to 5 minutes. Add the kale and cook, tossing, until wilted, 3 to 5 minutes. To the sausage and kale, add tomatoes, cream, Asiago, Parmesan, 1/3 cup water, 1/2 teaspoon salt, and 1/4 teaspoon pepper to the pot with the pasta. Stir to combine. 
3. Bake until the liquid is bubbling vigorously and the top is browned, 15 to 18 minutes. Let sit for 5 minutes. Serve topped with additional Parmesan.

*Vegetarian Sweet Italian Sausage Substitute

Ingredients

One package of MorningStar Farms Grillers Recipe Crumbles or other Soy/Vegetable Crumbles, like Boca
3/4 tbsp red wine vinegar
1/4 tbsp salt
1/4 tbsp freshly cracked black pepper
1/2 tbsp dried parsley
1/4 tbsp garlic powder
1/4 tbsp onion powder
1/4 tbsp dried basil
1/2 tsp paprika
1/2 tsp crushed red pepper flakes - optional
1/2 tsp ground fennel seed
1/4 tsp brown sugar
1/8 tsp dried oregano
1/8 tsp dried thyme

Cook crumbles according to package directions and flavor with spices above, to taste. Wilt the kale and then add cooked, flavored crumbles. Follow the rest of the directions above.