- Olive oil
- 5 ripe medium tomatoes
- 2 or 3 bunches baby fennel, about 12 small heads
- Salt and freshly ground black pepper
- 1 bunch rosemary
- 1 bunch thyme
- 4 cups water, plus more if needed
- 4 cups milk, plus more if needed
- 3 tablespoons butter
- 2 cups polenta
- 1/2 cup creme fraiche
- 1 cup Parmigiano-Reggiano, plus more for garnishing if desired
- 1/4 cup red wine vinegar
- 6 (6-ounce) mahi mahi fillets
Preheat oven to 350 degrees F.
Prepare 2 sheet pans by lightly rubbing them with olive oil. Cut each tomato in half horizontally and remove the tops from the fennel. On 1 sheet pan, arrange the tomatoes, cut side down, brush generously with about 1 tablespoon of olive oil and sprinkle lightly with salt and pepper and half of the rosemary and thyme sprigs. Repeat this process with the fennel bulbs, again brushing with olive oil, seasoning lightly with salt and pepper and using the remaining rosemary and thyme sprigs. Place both pans in the oven, and roast until the tomatoes are very tender and the fennel is tender and lightly caramelized around the edges, about 20 to 25 minutes. Set aside 4 tomato halves for the vinaigrette.
While the vegetables are roasting, in a large saucepan, bring the water, milk and butter to a boil. Add 2 1/2 teaspoons of salt to the water and, working quickly, whisk in the polenta. Whisk constantly for 3 or 4 minutes to prevent lumps. Simmer for 45 minutes partially covered, stirring every 10 minutes, until the polenta is smooth, thick, and creamy. Add the creme fraiche and 1 cup of the Parmesan, and stir until smooth. Check for seasoning and adjust consistency by adding milk or water to the polenta if necessary. Polenta may be made up to 20 minutes ahead of time and kept covered until ready to serve.
To make the tomato vinaigrette, in the blender combine the reserved tomatoes, the red wine vinegar, 1/4 cup of olive oil, 1/2 teaspoon salt and 1/8 teaspoon pepper. Puree until smooth. Strain through a sieve and set aside until ready to serve.
Season the mahi mahi fillets with salt and pepper. Heat a large saute pan, add 3 tablespoons olive oil, and, when hot, add the fish, in batches if necessary, and cook until fish is just cooked through and flakes easily, about 3 minutes per side. Remove fish from the pan and serve immediately.
Serve each portion of mahi mahi over 3/4 cup of the polenta, garnished with 2 pieces of roasted fennel, one roasted tomato half, and drizzled with the tomato vinaigrette. Garnish with extra Parmesan, if desired.