Season fish with 1/2 teaspoon thyme, 1/8 teaspoon salt and pepper. Heat oil in a medium skillet over medium heat. Add shallot, garlic and 1/2 teaspoon thyme; cook, stirring, until beginning to soften, about 1 minute. Add wine, tomatoes and the fish to the pan; bring to a simmer. Cover and cook until the fish is cooked through, 4 to 6 minutes. Transfer the fish to a plate; keep warm.

Whisk cream and cornstarch in a small bowl. Add to the pan, along with the remaining 1/2 teaspoon thyme and 1/8 teaspoon salt. Cook, stirring, for 1 minute. Divide the fish and sauce among 2 shallow bowls