Get a large pot of water boiling, and cook pasta according to package instructions to al dente.

Meanwhile, you can get the rest of the dish started.

Preheat oven to 350 degrees F. Grease 9x13" baking dish and set aside.

In large skillet, cook sausage until done.

Remove sausage from skillet and set aside on a plate.

In same skillet, add diced onion and olive oil, if needed. There will probably be some grease from the sausage leftover so you can cook the onion in that, too.

Cook over medium-high heat until slightly soft, about 4 minutes.

Add garlic and cook another minute.

Season with salt, to taste.

Add summer squash and green beans and cook another 6-8 minutes, stirring often. You want the squash and beans to be slightly cooked but not completely. Remove from heat and set aside.

In separate skillet, melt butter over medium heat.

Add flour and mix with butter to create a paste, cooking 1-2 minutes until the flour is slightly golden.

Slooooooowly add milk, whisking continuously to break up clumps until smooth.

Once all the milk is added, bring to a simmer, whisking often, and let simmer 10 minutes.

Add goat cheese, 1 cup of mozzarella, lemon zest, nutmeg, salt, and pepper. Stir continuously until cheese is all melted.

In large bowl, combine pasta, sausage, and veggies. Pour sauce over pasta mixture, stirring well to combine.

Transfer pasta into prepared baking dish.

Top with remaining 1 cup mozzarella cheese.

Bake in preheated oven for 20-25 minutes, until cheese is golden brown.

Serve immediately. Enjoy!