For the Pumpkin:
- Preheat the oven to 400 degrees. Place a wire rack on a rimmed baking sheet. Season the interior of the pumpkin with salt. Place the thyme, star anise, parsley, and bay leaf in the cavity. Place the pumpkin on the prepared baking sheet and roast it for 45 minutes until tender. Remove from the oven and cool at room temperature being careful not to spill the juices in the center.
- When the pumpkin is cool enough to handle, remove the thyme, star anise, parsley, and bay leaf from the cavity and pour the roasting juices into a container. Scoop out the flesh and place it into the blender with ½ cup of the roasting juices. Blend on high until very smooth, about 5 minutes.
- Use at once or put in a saucepan, cover, and hold on lowest possible heat for up to 20 minutes. Or put in a container, cool to room temperature, cover, and refrigerate for up to 2 days. Gently reheat in a covered saucepan over low heat right before serving.
For the Cobia:
Heat the grill to 400 degrees. Salt and pepper cobia and prep the grill with the canola oil so the fish doesn’t stick. Grill the cobia for two minutes per side, or until cooked through. Remove from the grill and finish with butter before serving.
For the Sauce:
Place the cream and truffle juice in a medium saucepan over high heat and bring to a simmer. Reduce the heat to medium-low and simmer slowly until the sauce coats the back of a spoon, about 10 minutes. Reduce the heat to the lowest setting, cover, and hold warm for up to 30 minutes.
For the Mushrooms:
- Clean the mushrooms with a toothbrush and warm water to remove any dirt on the cap. Then scrape the stems with a paring knife until they are clean. Slice the mushrooms into ¼-inch pieces.
- Place the vegetable stock in a large skillet over high heat. When the stock simmers, remove the skillet from the heat and add mushrooms. Season with salt. Allow the mushrooms to lightly poach just until tender, 1½ to 2 minutes. Serve at once.
For the Brussels Sprouts:
Place the stock and agave nectar in a large saucepan over high heat and bring to a simmer. Add the Brussels sprouts leaves and simmer for 1 minute. Add salt and stir to dissolve. Drain. The leaves should be almost raw and need to be served at once.
Spoon some of the pumpkin sauce on the middle of the plate and place cobia on top. Scatter mushrooms and Brussels sprouts leaves around the plate. Spoon truffle sauce on all components and serve.