I don't know the exact steps that TomTom requires, but here's what I do with my old Garmin StreetPilot...
With a route being followed, I do a search for a restaurant. When I've found a place that makes my mouth water, I can
a) Insert the location of that place into the route I'm currently following OR
b) Go directly to the restaurant as a new route.
Upon completing that mouth watering meal...
If I did option a), I continue my exisiting route as the restaurant was inserted.
If I did option b), I restart the original route and get back on that route in a manner that makes sense.
That may not be what you were asking at all, but it's sort of related.