Ive been exploring this type of diet recently (no added sugar, no grains, no beans, nothing deep-fried) and I'm curious as to where people have been dining out. I allow myself dairy, but I know a lot of people don't. Meat is good, fat is good.
While you can usually find at least one thing on a menu that fits the requirements, I'm looking for places where the food is delicious (steamed chicken & veggies at a Chinese place? Blah!), the menu lends itself better for this sort of eating (looking for protein/meat, not just salads), and they have fewer carb-laden temptations. There's also lots of sugar hidden in sauces, which can be an issue.
Madangsui and other Korean BBQ joints
Blue Smoke - some items are pre-sauced though
Hill Country - brisket, ribs, sausages, I just wish their desserts weren't so prominently displayed
Zabb Elee - I cheat when getting the green papaya salad though as the dressing must have some sugar
Shake Shack - burger without the bun
Pearl Oyster Bar - bouillabaisse, without the bread, tough to not get the lobster roll though!
DBGB - sausages, burgers, charcuterie, though it can be hard to make yourself skip the bread
Personally I find it difficult to do Japanese without wanting nigiri, and seafood without wanting a lobster roll, so I usually save those for a carb day.