If you haven’t cooked farro ahead and want to end up with up to 2 cups, start with ¾ cup uncooked farro and 3 cups water in a medium saucepan. Bring to a slow boil, then lower the heat and simmer gently with the cover ajar for 30 minutes, or until the water is absorbed. If using quick-cooking farro, follow package instructions. If you wind up with more than 2 cups cooked farro, save the excess for another use.
Transfer the cooked grain to a serving bowl.
Trim about an inch off the bottoms of the asparagus if they look woody; scrape bottom of stalks with a vegetable peeler if need be. You can skip this if the asparagus is slender and fresh. Cut into 1-inch lengths.
Steam the asparagus, peas (or edamame) in the same saucepan with a little water, just until bright green and tender-crisp. Drain, rinse with cool running water, then drain again.
Add the asparagus, peas, and remaining ingredients to the cooked grain in the bowl. Stir together completely. Serve warm or at room temperature.