Cook farro according to package directions. 

Meanwhile, in a medium skillet, heat to medium high heat. Add oil to pan.

When oil is warmed, add onion and zucchini. Cook, stirring occasionally, until onions are translucent and zucchini has begun to cook through, about 4-5 minutes. Sprinkle with salt & pepper and add garlic. Cook for one more minute, remove from heat.

Drain farro and place in a medium sized bowl while still warm. Add cooked vegetable mixture, grape tomatoes and remaining ingredients. Toss to combine.

Serve warm or at room temperature. Add feta just before serving.