1 Bring 2 cups water to a boil in a medium saucepan over high heat. Add ¼ tsp. salt. Slowly pour in cornmeal (or polenta) in a gentle stream, stirring rapidly with a whisk or wooden spoon to avoid lumps. Cook, stirring, until the mixture starts to thicken, about 3 minutes.

2 Reduce heat to a low simmer. Cook, stirring every 5 minutes, until the polenta easily comes away from the sides of the pan, 20 to 25 minutes. While stirring, crush any lumps against the side of the pan. If the polenta becomes too thick to stir, add ½ cup water. The final texture should be similar to a thick porridge. Remove from heat and cover to keep warm.

3 Meanwhile, heat oil in a large skillet over medium heat. Add celery; cook, stirring occasionally, until tender, about 5 minutes. Add garlic; cook until aromatic but not browned, 30 seconds. Stir in tomatoes, olives, basil, capers, ground pepper, crushed red pepper, and the remaining ¼ tsp. salt. Cover, reduce heat to low, and simmer for 5 minutes.

4 Place swordfish steaks in the simmering sauce. Cover and cook until the fish is cooked through, 10 to 15 minutes.

5 To serve, spoon the polenta onto a large serving platter. Arrange the fish over the polenta, top with the sauce, and garnish with fresh basil, if desired.

To make ahead: Refrigerate polenta (Steps 1-2) for up to 1 week. To reheat, combine with ½ cup water in a saucepan over medium heat, stirring occasionally.