adapted from Timeless Natural Food's "Jimbo's Mediterranean Farro Salad"
Bring the water to boil in a medium saucepan. Add the farro (or spelt berries) and salt, lower heat to maintain a gentle simmer. Cover and cook until grains are tender, about 15–20 minutes; drain off any excess water. Transfer cooked grain to a large bowl and let cool.
Make the dressing in a small jar—whisk to combine the vinegar, Dijon, pepper, and salt then while continuing to whisk, drizzle in the olive oil.
Add the vegetables to the cool farro (or spelt berries). Drizzle with the dressing and mix to combine. Crumble in the feta and mix gently. Store in the refrigerator. It'll keep well for a few days.