1 large or 2 small fennel bulbs, stalks and core removed, fronds reserved, and fennel bulb coarsely chopped1 large onion, peeled and coarsely chopped1 pint grape tomatoes, halved2 cloves garlic, peeled and minced¾ c. pitted Kalamata olives, coarsely chopped3 tbsp. extra virgin olive oil½ tsp. coarse kosher salt, plus more to taste¼ tsp. freshly ground black pepper1 tbsp. chopped fresh oregano, or 1 tsp. dried1 tbsp. fresh chopped basil, or 1 tsp. dried½ tsp. toasted and ground fennel seed (it can also be crushed with a knife blade)1½ cups dry orzo or 1½ c. pearled farro2 c. vegetable broth, plus more as needed, for cooking the orzo or farro (farro will take longer to cook)¼ c. reserved fennel fronds, chopped, plus additional for garnish½ c. panko breadcrumbs⅔ c. finely grated Parmesan cheeseAdditional extra virgin olive oil for drizzling over casserole before baking and servingFreshly ground black pepper, for sprinkling before serving
Preheat oven to 425 degrees. Line a 9-by-13-inch baking sheet (with sides) with parchment paper; set aside. Oil a 10-inch baking dish; set aside.
In a large bowl, mix fresh fennel, tomatoes, onions, olives and garlic together with 3 tbsp. olive oil. Add ½ tsp. salt, and all of the pepper, oregano, basil and ground fennel seed; mix again. Turn mixture out onto prepared baking sheet, making sure to spread everything out in a single layer. Bake for 20-25 minutes, or until the edges of the fennel begin to char; transfer pan to cooling rack. Reduce oven temperature to 400 degrees.
Heat broth in a large saucepan over medium-high heat. Add the orzo or farro and cook until just tender, about nine minutes for the orzo, and 15-20 minutes for the farro. (Add a tablespoon or two more liquid, if needed.) Drain in a colander set over a bowl; reserve the broth.
Fold the drained orzo (or farro) into the pan of vegetables, adding just a couple of extra tablespoons of the reserved broth. Stir in the fennel fronds. Taste, adding more salt as needed. Pour mixture into oiled baking dish. Gratin can be prepared to this point, covered with foil paper and refrigerated overnight.
In a small bowl, stir together the panko breadcrumbs and Parmesan cheese. Evenly sprinkle mixture over the top of the vegetables, drizzle with 1-2 tbsp. extra virgin olive oil, and bake for 20 to 30 minutes, or until casserole is hot and topping is golden brown.
Sprinkle with freshly ground black pepper, garnish with fennel fronds, and drizzle with your best olive oil; serve.
Makes 6-8 side dish servings.