Place the butter in a large skillet and set over medium heat. Once melted, add the chopped onions and celery. Sauté for 3-5 minutes to soften.
Meanwhile, chop all the herbs and whisk the chicken broth and eggs together. Pour the dried bread cubes into a large slow cooker.
Once the onions and celery are soft and sweet, scoop them over the top of the dried bread cubes. Add the chopped herbs, dried cranberries, 2 teaspoons of Diamond Crystal® Kosher Salt, and 1/2 teaspoon crushed red pepper. Pour the broth and egg mixture over the top. Gently mix to coat.
Cover the slow cooker and turn on high for 2-4 hours, or low for 4-6 hours. If you leave the stuffing on too long, and it starts to dry out, add a little more chicken broth to soften.
You can substitute 4 teaspoons sodium-free poultry seasoning for the fresh sage, rosemary, and thyme.Keep the stuffing on the crock pot "warm" setting when it's done cooking.