たまご
egg
tamago
JMdict 1549140
朝(あさ)ご飯(はん)for breakfastに卵(たまご)eggを焼(や)いたfriedよ
I fried an egg for breakfast
Here に (for) marks 朝ご飯(あさごはん) (breakfast) as the occasion the cooking is for, and を (object) marks 卵(たまご) (egg) as what was cooked. The verb 焼く(やく) (fry, grill) shifts to casual past 焼いた(やいた) (fried), and the final よ (emphasis) shares the news.