Place the farro with the sage and rosemary sprigs in a large saucepan and cover with 2 inches of water. Bring to a boil, reduce heat, and simmer, uncovered, until the farro is tender but still firm, about 30 minutes. Remove the sprigs and drain the farro. Let cool.

Whisk garlic, shallot, lemon zest, herbs, parsley, vinegar, salt and pepper. Slowly whisk in both oils.

In a large bowl, combine farro, tomatoes, onions, zucchini and spinach leaves. Toss with enough dressing to taste, reserving some to drizzle over the top. Season with salt and pepper.

Transfer to a platter, or individual plates, and drizzle with reserved dressing. Garnish with additional herbs, if desired.