Start by cooking the farro according to package directions until tender, then set aside to cool—this can happen while you prep everything else. While the farro cooks, finely chop the onion, mince the garlic, dice the tomatoes, chop the fresh mint, and crumble the feta cheese. Measure out all your spices (cinnamon, cumin, and cloves) into a small bowl. Having everything prepped and ready makes the cooking process smooth and prevents burning aromatics while you're searching for ingredients. Preheat your oven to 375°F.
While the farro cools, halve the 6 bell peppers lengthwise and remove the tops and seeds carefully. Arrange them cut-side up in a 9x13 inch baking dish—they should fit snugly. Set aside while you prepare the filling.
Heat 1.5 tbsp olive oil in a large skillet over medium heat. Add the chopped onion and minced garlic, stirring frequently until softened and fragrant, about 5 minutes. This builds a flavorful foundation for the lamb mixture. Don't rush this step—allowing the aromatics to soften properly develops deeper, more complex flavors.
Increase the heat to medium-high and add the ground lamb to the skillet, breaking it apart with a spoon as it cooks until browned, about 8 minutes. Once the lamb is no longer pink, add the spice mixture (cinnamon, cumin, and cloves) and stir constantly for about 1 minute to toast the spices and release their oils. I find toasting spices directly in the fat creates a richer, more aromatic flavor than adding them dry.
Stir in the diced tomatoes and tomato paste, mixing well to combine. Add salt and freshly ground black pepper to taste. Let this simmer for 2-3 minutes to allow the flavors to meld. Then add the golden raisins, pine nuts, and chopped fresh mint, stirring to distribute evenly. Cook for another minute until everything is well incorporated.
Fold the cooled farro from Step 1 into the lamb mixture, stirring until everything is evenly combined—the farro acts as a binder and adds texture. Divide the filling evenly among the prepared pepper halves in the baking dish, packing it gently into each one. Pour 1/4 cup water around the bottom of the dish (not over the peppers) to create steam during baking.
Cover the baking dish tightly with foil and bake at 375°F for 45 minutes until the peppers are tender. Remove the foil, top each pepper half with the crumbled feta cheese from Step 1, then switch your oven to broil on high and broil for 1-2 minutes until the feta just begins to char and bubble. I like to watch the broiler closely during this step—even 30 seconds too long can turn your beautiful feta bitter instead of melty and golden. Serve the peppers warm straight from the oven.