TO PREPARE THE TOMATOES: Preheat the oven to 375°. Bring a large pot of water to a boil. Blanch the tomatoes in the boiling water for 30 seconds and then peel off the skins. Cut each tomato into 8 wedges, place in a small roasting pan, and toss lightly with the garlic cloves, olive oil, balsamic vinegar, and thyme. Bake for 20 to 25 minutes, or until the tomatoes are soft. Remove the tomatoes from the pan, season to taste with salt and pepper, and keep warm. Strain the cooking liquid through a fine-mesh sieve and season to taste with salt and pepper. Keep warm.
TO PREPARE THE BROCCOLI RABE: Cook the broccoli rabe in the butter in a small sauté pan over medium heat for 5 minutes, or until warm. Season to taste with salt and pepper.
TO PREPARE THE COD: Warm the olive oil in a medium saucepan over a very low flame to 120°. Season both sides of the fish with salt and pepper and place in the warm oil. The oil should cover the fish. Cook for 9 minutes, turn the fish over and cook for an additional 9 minutes, or until just done.
Place some of the roasted tomatoes in the center of each plate and top with a piece of fish. Arrange the broccoli rabe around the plate and drizzle the tomato cooking liquid over the fish and around the plate.
insights: Poaching in oil may sound like it would produce oil-soaked fish, but it actually seals in the juices and results in tender, moist fillet. It is a good cooking technique for firmer fish such as cod, swordfish, or salmon. The key is for the oil to be warm, but not hot. Keep the thermometer in the oil as the fish is cooking, and adjust the heat to maintain a temperature of 110° to 115°.