Rosemary and Sage Stuffing Balls

Name: Rosemary and Sage Stuffing Balls
Ingredients: 25 slices white sandwich bread; 2 large onions, chopped; 1 bunch celery, diced; 1/2 cup chicken or turkey stock; 1 tablespoon butter; 1 tablespoon canola oil; 2 eggs, beaten; 1/2 ounce sage, torn; 2 tablespoons minced rosemary; 8 ounces sliced crimini mushrooms; 1 teaspoon white or black pepper; 1 teaspoon kosher salt