The Isthmus Peak Track is a much less crowded alternative to the now super famous Roys Peak Track, although I’ve heard it’s getting more popular. There are excellent views of both Lake Wanaka and Lake Hawea, and a good portion of the walk is on high ground in a conservation area.
There’s still a fair amount of time spent in farmland on the lower slopes, but I don’t remember this being quite as smelly and weed ridden as on Roys Peak. But this was in 2015, so things may have changed.
An obvious track with info on the DOC website. There’s also a longer track across the tops that can be walked or mountain biked.