Cook the Italian sausage in a skillet over medium heat, breaking it apart until browned, about 5-7 minutes. In a separate saucepan, melt the butter and sauté the diced onions and celery until softened, about 3-4 minutes. Combine cooked sausage with sautéed vegetables, then stir in the stuffing mix and chicken broth until moist.

Take the turkey breast and place it on a cutting board. Carefully slice horizontally, opening like a book, and pound to about ½ inch thickness. Season both sides with kosher salt and black pepper.

Spread prepared stuffing evenly on the flattened turkey breast, leaving a 1-inch border. Roll the turkey tightly from the longer edge, securing with kitchen twine every 2-3 inches.

In a small bowl, mix remaining softened butter with garlic powder, salt, and pepper. Rub this mixture over the roulade. Preheat the oven to 375°F and bake the roulade for 55-60 minutes, increasing the temperature to 400°F for the last 20 minutes.

Let the roulade rest for 15 minutes after reaching an internal temperature of 165°F. Slice into rounds and serve.