I am hosting a St. Patrick's Day party and will be serving a buffet dinner for approx. 25. I am serving beef stew braised in Guinness, a baked cod dish, mashed potatoes w/scallions (champ), sauteed cabbage and roasted tomatoes. Not concerned about the sides, but not sure how much chuck to get for the stew or how much fish for that matter. I will be serving some light apps for an hour or two before dinner. Any suggestions would be appreciated. Thanks.