Place chickpeas in a bowl and stir in the garlic, lemon juice, 1 tbsp olive oil, a pinch of salt, and (optionally) the chili flakes. Mix and set aside.
Toss leeks with the remaining oil and a pinch each of salt and pepper. Spread out on a baking sheet and roast in oven until golden brown, taking care not to burn them, about 20 minutes. Toss them half way through.
When the leeks are done, add them to the chickpeas along with the farro and toss everything. Taste for salt and pepper. Add more lemon juice if necessary.
Garnish with the parsley and serve warm.
Recipe by Oishii Rasoi at https://www.oishiirasoi.com/farro-salad-with-chickpeas-and-roasted-leeks/