Two great cauliflower textures in one dish: caramelized florets and silky puree.
1. Preheat oven to 350°.
2. Remove crust from bread. Tear bread into very small pieces. Place on a baking sheet, and bake at 350° for 13 minutes or until toasted and golden brown, stirring occasionally. Remove from oven. Increase the oven temperature to 450°.
3. Cut cauliflower into 2-inch florets, reserving stems. Place florets on a foil-lined baking sheet. Drizzle with 1 tablespoon olive oil; toss well. Bake florets at 450° for 25 minutes or until dark golden brown in spots and almost tender. Sprinkle florets with 1/8 teaspoon salt and pepper.
4. Combine reserved cauliflower stems and 2 cups water in a small saucepan over medium heat; bring to a boil. Cover, reduce heat, and simmer 10 minutes or until very tender. Drain well. Place stems, remaining 1/8 teaspoon salt, and juice in a food processor; process until smooth.
5. Combine parsley, garlic, and rind in a small bowl. Combine mustard and vinegar in a small bowl. Gradually add remaining 4 teaspoons extra-virgin olive oil and canola oil to mustard mixture, stirring with a whisk.
6. Heat a large skillet over medium-high heat. Coat pan with cooking spray. Add cauliflower florets; sauté 1 minute or until thoroughly heated. Stir in capers and parsley mixture. Sprinkle with breadcrumbs. Place 2 tablespoons cauliflower puree on each of 6 plates. Top each serving with 3/4 cup floret mixture; drizzle with 2 teaspoons vinaigrette.