Place 1½ cups farro in a dry medium saucepan; cook over medium-high heat, shaking the pan occasionally, until very fragrant, 3 to 4 minutes. Add 3 cups water; bring to a boil over high heat. Reduce heat to medium-low; cover and cook until tender, 20 to 25 minutes. Drain and rinse under cold water until cool, about 1 minute. Transfer the cooled farro to a large bowl. Add 6 cups cabbage, 4 cups broccoli, 1 (15-ounce) can chickpeas, 1 cup feta, ½ cup olives, ½ cup parsley and ¼ cup dill.
Wipe the saucepan clean. Add 1 cup oil; heat over medium heat until shimmering. Add ½ cup almonds; cook, stirring often, until lightly toasted, 2 to 3 minutes. Add sliced garlic, 1 teaspoon each cumin and salt and ¾ teaspoon crushed red pepper; cook, stirring constantly, until fragrant, about 1 minute. Immediately pour over the vegetable mixture in the bowl. Add 6 tablespoons vinegar; gently toss to combine. Garnish with additional parsley and dill, if desired.
