Where do you find you are the most and the least successful in maintaining your mindfulness? The environment where you eat (where you do anything, really) plays a role in the ultimate success or failure of your endeavor.
As Seth Godin has said:
Most of all, I think we can train ourselves to associate certain places with certain outcomes. There's a reason they built those cathedrals. Pick your place, on purpose.
Give some thought to where you are most successful cultivating real-time mindfulness. Can you make sure you eat there more often?