If somebody asked me, ''have you had your lunch?'' then what should I say? ''Yes, I have had my lunch'' or I might say " yes I had lunch"

What suppose I say if ... (What would I say ...) If somebody asking me, ''have you have your lunch?'' (If someone asked me, "Have you had lunch?") then what should I say? (then what would I say?) ''Yes, I have my lunch'' or ''Yes, I had my lunch'' (Yes, I have had my lunch.)

All the other answers are correct. However, in informal speech of everyday, I would say, "Yes, I did." is sufficient.