1. Cook the spelt in plenty of salted water following the package instructions, then drain and cool. 2. Wash the grapes and cut the berries in half. 3. Crumble the feta with your hands or a fork. 4. In a large bowl, combine the cold spelt, grapes, feta, chopped walnuts, and arugula. 5. Season well with extra virgin olive oil, balsamic vinegar, salt, and pepper. 6. Mix well and serve the salad fresh or at room temperature.