Brunch between Plainfield and Flanders-or thereabouts..................
Rod's in Convent Station has a wonderful brunch. They are located between Morristown and Madison on Rte 124. http://www.rodssteak.com/sundaybrunchmenu.html I love the live piano music they have at the brunch service.
I do not recommend the Old Mill Inn in Basking Ridge. The restaurant, called The Grain House does do a sunday brunch, but when we went, we were totally disappointed. Not much of a spread, no service, the "chef" at the omelet station seemed to be annoyed we were ordering an omelets, wanting only a little ham and no cheese on one and a western with tomato for another, despite the menu specifically stating that omelets were "made to order". The hot bar was being dismantled as we arrived, even though the brunch was not scheduled to end for another hour+ We had 12:30 reservations, and had to wait for 15 min to be seated. (brunch is supposed to be served until 2pm) So although we paid for brunch we basically got an omelet a little fruit, some OJ, which we had to chase down 3 people to get, and a danish. No carving station, no deserts, no seafood.
In Mendham, the Blackhorse Inn Tavern and Pub also does a Sunday Brunch. Great food, but always crowded, and can get noisy. You always have to wait, sometimes for quite a while, despite reservations. Parking is by valet. http://www.blackhorsenj.com/black-horse-tavern-and-pub.aspx
If you really want to make it something special, consider doing the Sunday Lunch Buffet at 90 Acres at Natirar. Located high atop a mountain on 500 beautiful acres, on the Peapack/Far Hills border. Breathtaking place, amazing food and wine. You need reservations, and it is pricy, but oh god, is it wonderful. Absolutely top notch food and service. You'll feel like royalty. Eating there is an event. http://natirar.com/index.php/