For Smoking: Preheat homestyle smoking unit according to manufacturer's instructions. Pre-soak any wood chips such as pecan or hickory in root beer for a unique flavor. Combine all the above ingredients, blend well and pour over catfish fillets. Allow to set at room temperature approximately thirty minutes. Smoke fillets for approximately thirty-five to forty minutes or until flaky. Remove and allow to cool. For Terrine: Coarsely chop smoked catfish. In a two quart mixing bowl, add all remaining ingredients, blending well to incorporate seasonings into the mixture. Adjust salt and pepper if necessary, and pour mixture into a terrine mold. Place in refrigerator covered overnight. When serving, remove from mold and garnish with French bread or garlic croutons. To enhance the presentation of the smoked terrine, you may wish to color two cups of mayonnaise, one with red food coloring and one with green. Using a pastry bag with a star tip, pipe colored mayonnaise around the base of the terrine. You may also wish to garnish the tip of the terrine with a small amount of the colored mayonnaise and a fresh tomato rose.