1. Preheat oven to 350 degrees Fahrenheit.
2. Slice off ends of the spaghetti squash. Cut the squash down the center, long end. Then scoop out the seeds and set aside.
3. Place the squash face down in a long pan with high ends, or pyrex. Pour water into the pyrex.
4. Bake for 30 to 40 minutes until a fork smoothly punctures the center of the squash skin. As soon as the squash comes out of the oven, turn it face up.
5. Raise oven temp to 425 degrees Fahrenheit. Using a fork, rake some of the squash meat into its center.
6. Pour half a cup of tomato sauce into each squash cavity. Sprinkle cheese on top and then the feta cheese.
7. Bake in oven on 425 degrees Fahrenheit for 15 to 20 minutes until the cheese melts and browns at the edge.