Roast the pecans in a 350 degree oven for about 10 minutes. Make sure that you watch them. Nothing is more frustrating (or expensive) than burning 4 cups of pecans. Not that I speak from experience or anything, but nuts go from perfect to burnt in seconds.
Finely chop the rosemary.
Zest 3 oranges. I got about a Tablespoon of zest from each.
Melt the butter in a large saute pan.
Add the pecans, sugar, salt, rosemary, and orange zest.