There are few on this site. I found JoshStanley27's
Stan's Imperial Honey Porter and Romulan42's
Chocolate Honey Porter. Neither has been extensively reviewed.
But I adapted the White House Honey Porter recipe and came up with the following:
Volume 5 gallons
Grain
8 lbs. Pale two-row
1 lb. C20L
12 oz. Munich
6 oz. Black malt (although I might swap this out for roasted barley)
3 oz. Chocolate malt
1 lb. Honey
Hops
0.5 oz. Tettnang for 45 minutes
0.5 oz. Tettnang for 30 minutes
1 oz. Hallertau for 5 minutes
Yeast
They used Nottingham, but I'd use S-04 (if dry), or either Wyeast 1028 London or Wyeast 1084 Guinness (if liquid).
OG 1055,
FG 1014,
IBU 17,
SRM 19.
It's not quite true to style for either robust or brown porter, and my tweaking of the recipe boosts the IBU slightly, from 11 to 17 (which is still low for style, if that matters to you). You can, of course, tweak it yourself all you like, or go in another direction entirely. Post your result.
