Rinse the farro under cool water.

In a medium pot, combine farro, water or broth, a generous pinch of salt, and the bay leaf if using. Bring to a boil, then reduce to a gentle simmer. Cook until the grains are tender with a pleasant chew. Pearled farro often cooks in 15 to 20 minutes. Semi pearled may take 25 to 30 minutes. Whole farro can take up to 35 minutes. Taste as you go. You want a tender edge and a chewy heart. Drain any excess liquid. Discard the bay leaf. Spread the farro on a tray to steam dry for a minute so it does not water down the dressing.

Preheat the oven to 425 degrees Fahrenheit.

Line a rimmed sheet pan with parchment for easy cleanup. Scatter the grapes on the pan. Drizzle with 1 tablespoon olive oil. Season with a pinch of salt and a few grinds of pepper. Toss to coat and spread into a single layer.

Slide the pan into the hot oven. Roast for 12 to 15 minutes, shaking once, until the grapes slump, blister, and release a little syrup. You want them soft but still holding their shape. Set aside to cool slightly. The warm juices will help dress the farro.

While the grapes roast, place hazelnuts on a small pan and toast in the same oven for 6 to 8 minutes until fragrant and lightly browned. Rub the warm nuts in a clean kitchen towel to loosen most of the skins. Do not worry if some skins remain. Chop the nuts roughly. You want texture.

In a large mixing bowl, whisk together the remaining 1 tablespoon olive oil, lemon juice, Dijon, honey or maple, shallot, chopped rosemary or thyme, lemon zest if using, a pinch of salt, and a few grinds of black pepper. Taste and adjust. If your grapes are very sweet, add an extra squeeze of lemon. If the dressing feels too tart, add a touch more honey or oil.

Add the warm farro to the bowl with the vinaigrette. Toss until the grains gleam and absorb the dressing. Let the farro sit for 2 to 3 minutes. This rest helps the grains drink in the seasoning.

Tip the roasted grapes and their juices into the bowl. Gently fold to keep the grapes mostly intact. Add most of the chopped hazelnuts, reserving a small handful for garnish.

Scatter in the arugula or baby kale. Toss until the greens wilt slightly from the warm grains and grapes. Add chopped parsley or chives.

Taste and adjust with salt, pepper, and an extra drizzle of olive oil if needed. Crumble feta or goat cheese over the top if using. Sprinkle with the reserved hazelnuts. Serve warm, at room temperature, or chilled. It is beautiful in a wide shallow bowl.