I have not had this problem yet as I am still slowly losing weight on LCHF. I suppose at some point I will need to think about maintenance of a healthy weight and blood glucose level.But off the top of my head why not try:
Full fat creamy cheese like Brie, Cheddar, Gouda etc and lots of it.
Tuna or swordfish steaks, nice meaty fish.
Stews or homemade soups, there is a thread here specifically for this.
Try baking low carb breads and add pate and cold meats.
Cream in coffee or just cream and berries.
I am sure I read some years ago that passengers on the QE2 ocean liner ate so many calories that on average they gained between 1 and 2 pounds per day!
Perhaps not a good idea but a happy medium may work.