This recipe originally appeared on the Rachael Ray Show. For more recipes and videos from the show visit RachaelRayShow.com .
For the Fennel, Pepper and Onion Sauce:
- 2 tablespoons olive oil
- 1 small bulb fennel, quartered, cored and thinly sliced
- 1 cubanelle pepper, halved, seeded and thinly sliced
- 1 red field/bell pepper, seeded, quartered and thinly sliced
- 1 onion, quartered and thinly sliced
- 4 cloves garlic, thinly sliced
- Salt and pepper
- 1 28-ounce can Italian tomatoes
For the Roasted Broccoli Rabe:
- 1 large or 2 medium head/bunch broccoli rabe, trimmed of tough ends
- About 2 tablespoons EVOO 
- 4 cloves crushed garlic
- 1 red chili pepper, sliced
For the Herb-Walnut Pesto:
- 1 packed cup parsley and basil combined
- 3 tablespoons walnuts, toasted
- 1 large clove garlic, crushed
- A small handful grated Parmigiano-Reggiano cheese
- 1/4 cup EVOO  – Extra Virgin Olive Oil
- 4 large, soft, Italian hoagie rolls
- 1/2 pound mozzarella, sliced in half moons or deli-sliced provolone, sliced into half moons
Preheat oven to 400°F.
For the sauce, heat a heavy Dutch oven  or deep skillet over medium-high heat and add olive oil, 2 turns of the pan . Add fennel, peppers, onions, garlic and some salt, and cook, partially covered, until soft, about 10 minutes, stirring occasionally. Hand-crush tomatoes and add them and their juices to the pan . Simmer over medium-low heat for 20 minutes.
Meanwhile, bring a few inches of water to a boil in a deep skillet. Salt the water, add broccoli rabe and cook 3 minutes; drain. Arrange broccoli rabe on a baking sheet  lined with foil or parchment, dress with EVOO, salt, crushed garlic and chilies. Roast the broccoli rabe until crispy at edges and tender, 15-18 minutes.
For the pesto, process the herbs, walnuts, garlic and cheese into a fine chop. Stream in oil with the machine running to form a pesto sauce. Season with salt and pepper to taste.
Place a rack in the upper third of the oven. Split hoagie rolls lengthwise and spread both sides lightly with pesto, reserving the extra. Toast rolls in oven for 3-5 minutes, remove and switch oven to broil.
Fill the toasted rolls with some roasted broccoli rabe, top with the fennel, peppers and onions and some mozzarella or provolone. Melt cheese under broiler, dot with extra pesto sauce and serve.