Yes, I know, green beer and corned beef are not Irish traditions. But it's beer (mmmmm -beer). So what if it's green (use a drop of blue to make your own, remember the color wheel from grade school?).
Corned beef is not the most healthy meat, so why not once a year for St. Patrick's day?
What is really Irish, and what completes the meal, is soda bread:
6 c. flour
2 t. baking soda
2 t. baking powder
3 T. cornstarch
2 t. sugar
1/2 t. salt
1/2 cup currants
2 1/2 c. buttermilk
Mix dry ingredients in a large bowl. Add buttermilk and mix until a lumpy ball is formed. Knead for a minute or two. Divide dough into two balls and press slightly to flatten them. Place on ungreased baking sheet (parchment is recommended) and slash a cross in the top of each with a razor or very sharp knife. Rest for 10 minutes, then bake for 40 minutes or until loaves are golden brown. Cool on racks. Great as is, or sliced and toasted.