How To Fulfill Eating Shabbat Second Meal

You must eat a second meal on Shabbat (or Jewish festival) day with at least 1.9 fl. oz. (56 ml, 1/4 cup) of bread--even if you already said ha'motzi but ate less than 1.9 fl. oz. of bread at kiddush.  
Note Ideally, begin your second meal before halachic midday. But you may eat your second meal anytime after shacharit and before sunset.