Recipe: Broccoli Reuben Sandwich

Name: Recipe: Broccoli Reuben Sandwich
Ingredients: 1 pound broccoli (about 3 stalks), florets cut into very small pieces and stalks peeled and cut into rounds (4 cups florets and 2 cups stalks); 3 tablespoons olive oil; 1/2 teaspoon kosher salt; 2 cloves garlic, minced; Freshly ground black pepper; 1/4 cup mayonnaise; 1 teaspoon Sriracha hot sauce; 4 slices rye or pumpernickel bread; 1/2 cup drained sauerkraut; 4 slices Swiss cheese (2 ounces); 1 tablespoon unsalted butter, at room temperature, divided