Lay the turkey breast flat on a clean surface. Use a meat mallet to gently pound it to an even thickness.

In a skillet, melt 2 tablespoons of butter over medium heat. Add the diced onion and celery. Sauté until soft, about 5 minutes.

Add the sausage. Cook until browned, about 8-10 minutes.

Once the sausage is cooked, add the stuffing mix and chicken broth. Stir to combine. The mixture should be moist but not too wet. Adjust with more broth if needed.

Preheat your oven to 350°F (175°C). Spread the stuffing evenly over the turkey breast. Roll it tightly, starting from one end. Secure with kitchen twine or toothpicks.

Melt the remaining butter and mix with salt, pepper, and garlic powder. Brush this mix over the outside of the rolled turkey.

Place the roulade in a baking dish. Bake for about 1 hour, or until the turkey reaches an internal temperature of 165°F (74°C). Let it rest for 10 minutes before slicing.