I'm sure this is technically possible, but it may never be practical. Much like human operators, you're going to want to drive the user down a certain path, because order is often extremely important.
What if Dominoes doesn't have green peppers? What if they don't like the pizza brand? What if they're asking because they have a coupon? You may end up repeating sections of the conversation multiple times, and in the end the user will just end up so confused they give up.
More importantly, how do you know Dominoes (or someone else with an incentive) is not driving you down a certain path?
This happens today already with Ads, Fb feed, instagram etc... but there is something distinctly suspicious about taking away specific control points in the decision making process.
What if Dominoes doesn't have green peppers? What if they don't like the pizza brand? What if they're asking because they have a coupon? You may end up repeating sections of the conversation multiple times, and in the end the user will just end up so confused they give up.