Preheat the oven to 400°F (200°C). Cook farro according to package instructions; set aside. In a large skillet, heat olive oil over medium heat. Sauté the diced onion with ½ teaspoon salt for 8-10 minutes until softened. Add the minced garlic and cook 1-2 minutes until fragrant.

In a large bowl, combine the warm sautéed onions and garlic with the cooked farro, chickpeas, and harissa paste. Mix thoroughly to let the harissa melt into the mixture. Gently fold in the cubed feta cheese and chopped parsley. Add the remaining ½ teaspoon salt and ½ teaspoon black pepper, and stir just until combined.

Arrange bell pepper halves on a parchment-lined baking sheet. Spoon the filling into each pepper, pressing gently to pack.

Bake for 30-35 minutes, until the peppers are tender and golden at the edges. Let rest before serving. Garnish with extra parsley or a drizzle of olive oil if desired.