Roasted Broccoli Steaks with Tomato Butter and Tapenade

Name: Roasted Broccoli Steaks with Tomato Butter and Tapenade
Ingredients: 2 ounces bakery white or rye bread, torn into small pieces (about 1 cup); 6 tablespoons olive oil, divided; 3 1/2 teaspoons kosher salt, divided; 1 3/4 teaspoons black pepper, divided; 2 medium broccoli heads, stems trimmed to 3 inches and heads cut lengthwise into 8 (3/4-inch-thick) steaks; 2 cups cherry tomatoes (about 10 ounce); 1 small red onion, cut into 1-inch wedges (root trimmed); 4 to 8 tablespoons unsalted vegetable stock; 2 tablespoons unsalted butter, chilled and cut into 1/2-inch pieces; 1/4 cup jarred tapenade (such as Divina Olive Bruschetta)