Place spaghetti squash, cut sides down, on a lightly greased baking sheet. Bake for about 45 minutes, until a sharp knife can be inserted with little resistance. Remove from oven and let cool.
Meanwhile, in a large skillet, saute garlic in hot oil for 1-2 minutes. Stir in tomatoes and cook until warmed through
Using a large spoon, scoop the stringy pulp from the squash.
Add to skillet and toss with vegetables, feta cheese, olives, and basil. Serve warm.