Dry stout? Probably the simplest extract/specialty grain recipe I've got in my book.
5 lbs. Dark DME
1 lb. roasted barley
3 oz. Willamette pellets @ 4%AA - 60
Bring 2.5 gallons to boil in main kettle. In another smaller kettle, add roasted barley to 1/2 gallon cold water and bring to "damn near"* boil. Strain this liquor to main kettle. When this 3 gallons comes to the boil, remove from burner. Add DME. Return to heat, stirring constantly. Return to boil. Boil 60 minutes with full hops charge. At 45 mins, add kettle clarifier, if any (I use Whirlfloc and Yeastex for nutrient). Cool using your normal method, and pitch a nice, clean ale yeast.
My brews of this stout usually ferment to completion within three or four days, after which I immediately rack to a secondary for seven days, just to stabilize flavor. Package however you like.
I don't use flaked barley because: A.) it needs to be mashed and this is an extract beer; and B.) I don't have problems with head retention. When I add flaked oats, I call it something else; a dry stout is different from an oatmeal stout.
Try it; if you find it a bit thin, a half-pound of Belgian Biscuit might help mouthfeel.
* This is a technical term.
I don't bother with a thermometer to judge this; I just wait for that glassy look water gets when it's really close to boiling, but not quite there. I learned this while studying historical brewing techniques to judge when mash liquor was at a good mashing temperature, and it's not as hard as it sounds.