Step 1Bring a large pot of water to a boil. Meanwhile, spiralize the squash using the slicer blade. Take up handfuls and cut into manageable lengths, then transfer to a large bowl and set aside.
Step 2To the boiling water, and add the green beans. Blanch until just tender, 4 to 5 minutes, then transfer to a bowl of cold water. Drain and set aside.
Step 3In a large, heavy skillet, heat 1 tablespoon of the olive oil over medium-low heat. Add the garlic. Cook gently, stirring, until translucent, about a minute, then stir in the green beans and herbs. Remove from heat.
Step 4Bring the water in the pot back to a boil and add the squash ribbons. Cook 30 seconds to 1 minute to soften. Drain the squash noodles and add to the pan with the green beans and herbs. Add the remaining olive oil, salt to taste, black pepper and the feta, and toss together using tongs. The squash will continue to release water, so the mixture will be moist. Use tongs to serve.