Preheat the oven to 375 degrees F.
Cut the spaghetti squash in half lengthwise and scrape out the seeds. Place the squash halves, cut side down, in the bottom of a roasting pan. Add olive oil and enough water to cover the bottom of the pan and cover the roasting pan with aluminum foil. Bake for about 1 1/2 hours, or until the squash is tender. Allow to cool slightly and then run a fork through the squash flesh to release the squash in strands. Toss the squash with the butter, salt and pepper, to taste, the minced chives, red pepper, and garlic. Cover to keep warm and set aside.
While the squash is cooking, prepare the Fennel Vinaigrette. In a medium skillet, heat the oil over high heat. Add the fennel and saute until tender, about 6 minutes. Add the red onion, garlic, and fennel seed and cook, stirring, until onion is soft and garlic is fragrant, 3 minutes. Add the tomatoes and wine and cook until the wine has evaporated, 2 to 3 minutes. Add the red wine vinegar, herbs, salt and pepper and remove from the heat. Transfer to a nonreactive bowl and allow to cool to room temperature while you prepare the catfish.
Season the fillets on both sides with the Essence. Rub the flesh side of each fillet with 1 1/2 teaspoons of the mustard. Squeeze the grated potatoes with your hands to release any liquid and then divide the grated potatoes between the 4 fillets, pressing onto the flesh side on top of the mustard coating.
Increase the oven temperature to 425 degrees F.
Heat 1/2 cup of the vegetable oil in each of 2 large nonstick skillets over medium-high heat. When the oil is hot, carefully add the fillets, potato side down, being careful to keep the potatoes on the fish. Cook until the potatoes are crispy and golden, about 4 minutes. Transfer to the oven and cook until the catfish is cooked through, about 10 minutes. (Cooking time will vary depending on the thickness of your fillets.) Remove from the oven. Spoon some of the spaghetti squash onto the center of 4 plates, and serve the fillets over the spaghetti squash. Divide the Fennel Vinaigrette among the tops of the fillets, about 1/3 cup each. Serve immediately.
Yield: 4 servings