Bring a large pot of water to a boil. Salt the water and cook the green beans until crisp-tender, 2 minutes. Using a slotted spoon, transfer the green beans to a colander; rinse in cold water until cool. Chop into bite-size pieces.
Add the farro to the pot of boiling water and cook, stirring occasionally, until just tender, 18 to 22 minutes. Drain the farro and spread out on a large plate; let cool. Season with salt and pepper.
Meanwhile, place the eggs in a small saucepan with a lid; add enough water to cover the eggs by 2 inches. Bring to a boil; remove from the heat. Cover and let stand 9 minutes; drain and let cool. Peel under cold running water; pat dry and quarter lengthwise.
In a medium bowl, whisk the lemon zest and juice, tahini, garlic and 4 to 6 tsp. water until smooth; season.
In a 3 1/2 - to 4-quart trifle bowl, evenly layer the romaine, beets, farro, eggs, green beans, chickpeas, olives and then the herbs, seasoning the layers as you go. Serve with the dressing for drizzling.
The Gotta-Know Guide to Olives