Cook the Farro: Bring a medium pot of salted water to a boil. Add pearled farro and simmer 15–25 minutes (per package) until tender with a pleasant chew. Drain well and spread on a baking sheet to cool to room temperature.
Toast the Walnuts: Meanwhile, toast walnut halves in a dry skillet over medium heat, stirring, 3–5 minutes until fragrant and lightly browned. Transfer to a plate to cool, then roughly chop.
Make the Vinaigrette: In a large serving bowl, mash half the avocado until mostly smooth. Add lemon zest and juice (about 3 Tbsp), garlic, Dijon, oregano, smoked paprika, salt, and pepper; whisk to form a thick paste.
Emulsify: While whisking constantly, slowly drizzle in the olive oil until smooth and creamy.
Assemble: Add cooled farro, well-drained chickpeas, cucumbers, tomatoes, roasted red pepper, and red onion; gently fold to coat evenly.
Finish: Dice the remaining avocado half. Add with parsley, dill, and toasted walnuts; fold gently once or twice. Taste and adjust salt, pepper, or lemon.
Serve: Divide among 4 bowls and serve immediately for best color and texture.