- Preheat oven to 375°F. Line large rimmed baking sheet with nonstick foil.
- Trim green leaves and stem from cauliflower, leaving core intact so slices hold together. Cut cauliflower into 3/4-inch-thick slices.
- Spray large skillet with nonstick spray and set over medium-high heat. Add cauliflower in batches and cook until browned in spots, about 3 minutes per side. Transfer to prepared baking sheet in single layer. Spray cauliflower lightly with nonstick spray. Sprinkle with 1/2 teaspoon of salt and lemon zest. Bake until tender, about 20 minutes.
- Meanwhile, stir together tomato, basil, vinegar, oil, garlic, and remaining 1/4 teaspoon salt in small bowl. Transfer cauliflower to serving platter and spoon tomato mixture on top. Sprinkle with Parmesan shavings.
- Per serving: 1/4 of cauliflower and about 2 tablespoons vinaigrette
When cutting the cauliflower into slices, don't worry if some small pieces fall away from the slices. Once roasted, they will be just as delicious as the pretty cauliflower "steaks."