01 - Rinse the farro under cold water. In a medium saucepan, combine farro, water, and salt. Bring to a boil, then reduce heat and simmer uncovered for 20-25 minutes, until tender. Drain and let cool.
02 - Bring a pot of salted water to a boil. Add asparagus and cook for 2 minutes, then add peas and cook for 1 minute more. Drain and immediately transfer vegetables to a bowl of ice water to stop cooking. Drain again and set aside.
03 - In a small bowl, whisk together olive oil, lemon juice, lemon zest, Dijon mustard, garlic, dill, salt, and pepper.
04 - In a large bowl, combine cooled farro, blanched asparagus, peas, radishes, and arugula. Drizzle with dressing and toss gently to coat.
05 - Transfer salad to a serving platter or bowl. Sprinkle with feta and pine nuts. Serve immediately or chill for up to 4 hours.