Looking on the internet deeply has found these results:

I will have lunch is the most popular phrase on the web.

I'm going have lunch 110 results on the web	I will have lunch 1325,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
You know, I'm going to go have lunch with my daughter. I'm not going to lunch with you, Nikolai. I'm not going to lunch, Thatcher. I'm going for lunch buddies with privileges. We went through New York... and I seem to remember going to lunch, I'm still a little vague... I don't know what you two are playing at. I'm going for lunch. And I'm not going to have lunch with Miss Kittredge, or dinner. That's swell of you, but I'm going to have lunch.	First off, I am plugging your 4th of July party as the reintroduction of the happy Grayson clan, followed by a mother/daughter law goodwill tour that I will lay out for you when the three of us have lunch tomorrow. I told Grace I'd have lunch with her. I will have lunch with Clas Greve on Monday... in Okay mom. I will have lunch, I will have everything shipshape by lunch. I thought maybe I'd invite Jack to have lunch with me today.

I'm going have lunch

110 results on the web

I will have lunch

1325,000 results on the web

More popular!

You know, I'm going to go have lunch with my daughter.
I'm not going to lunch with you, Nikolai.
I'm not going to lunch, Thatcher.
I'm going for lunch buddies with privileges.
We went through New York... and I seem to remember going to lunch, I'm still a little vague...
I don't know what you two are playing at. I'm going for lunch.
And I'm not going to have lunch with Miss Kittredge, or dinner.
That's swell of you, but I'm going to have lunch.

First off, I am plugging your 4th of July party as the reintroduction of the happy Grayson clan, followed by a mother/daughter
law goodwill tour that I will lay out for you when the three of us have lunch tomorrow.
I told Grace I'd have lunch with her.
I will have lunch with Clas Greve on Monday...
in
Okay mom. I will have lunch,
I will have everything shipshape by lunch.
I thought maybe I'd invite Jack to have lunch with me today.