I always like adding oregano and thyme (not either one, have to be both!) in potato. They're the herb I put into these burger "buns", which are actually mashed potato coated with nut, bread crumb and Parmesan. Sandwiched between the buns are balsamic vinegar glazed onion from Sher .
I'd suggest you going to Sher's blog to look at the onion she made, it has a beautiful ruby color. Mine doesn't get such an attractive color as I didn't use red onion as specified, but the taste is fantastic... tangy and caramelizing sweet; perfect with grilled vegetable, fish, meat ... oh, almost everything!
To make potato "bun", I used Yukon Gold (nicer color and flavor), cooked, mashed, added butter, oregano & thyme, Parmesan and salt. Shaped it with a 5 cm (2 inches) round mould or cookie cutter.
For coating, it included ground almond, bread crumb (made it from good artisanal bread) and Parmesan. The ratio is about 1 : 1 : 0.3.
Heat some oil in a fry pan, coated the "buns" with the nut mixture, fry them over medium heat until golden brown.