Preheat oven to 425 degrees

Place prepared pie crust in pie pan, fluting the edges and poking the bottom of the crust with a fork

Add olive oil to a large skillet and saute onion for about 10 minutes over medium heat

Add squash and cook for another 10 minutes or until vegetables are soft and beginning to caramelize

Season with salt & pepper and place in prepared pie shell

Crumble goat cheese over the vegetables

Whisk together eggs, milk and cream with a little more salt & pepper and pour over the goat cheese & vegetables

Top with sliced tomatoes 

Bake for 25 to 30 minutes or until custard sets and top begins to brown a little