This is a nice, fairly fancy-looking hors d'oeuvre that also works for people on certain types of fad diets since it contains very little carbohydrate.

It's also very pretty.

What You Need

Get the thicker, shorter "American" kind (I'm not sure of its actual origin but it's what we usually have here) rather than the long skinny English or Japanese varieties. The American ones don't have as much flavor but their main function in this recipe is to hold stuff rather than add to the taste, so bigger is better in this case.

Sour Cream
I would go with the full-fat kind, but really the lower-fat versions of sour cream are surprisingly less horrible than you might imagine, if fat is a concern.

Smoked Salmon
When I made this, I didn't use lox but rather the drier, more cooked-seeming kind, which was what I had on hand, but I bet it would be good either way.

Let us just pause for a moment and admire the caper. What an excellent, versatile food. Yay.

Fresh is always good, but dried works just fine here. This should be the leaves (often called "dill weed" for some reason), rather than the seeds.

Dry Mustard

Salt and Cracked Pepper

What To Do

Wash the cucumber(s). Try to get an unwaxed one if you can. If it is waxed, you may want to completely peel it, though eating the wax will not hurt you. It is, after all, food-grade wax. But still, ew.
You might also want to try peeling it in strips, to give an attractive striped appearance to the final product. Some people also drag a fork vertically down the skin for a stripy look, but I think the peeling-strips method looks nicer and involves less danger of death by fork.

Slice the cucumber into 1/4-inch-thick rounds. Blot dry.

Mix the sour cream with an appropriate amount of dill and mustard. Don't use very much mustard to start out with--you can always add more but you can't take it out. Season to taste with salt and freshly ground pepper.
(I have to say, I have always hated the word "freshly" but I can't think what else to use in this situation. Any suggestions would be welcome.)
When I was making this, I thought some onion salt might be good in it, but I didn't have any at the time. You might try it and let me know if it's any good.

Divide the salmon into small pieces.

Spoon a little of the sour cream on each cucumber round, and top with a piece of salmon.

The thing with the capers is, I can't decide whether they would be better on top of or under the salmon. They would stay on better if you put them underneath, but they would look prettier on top. You decide.

Either way, put the capers on, and serve.

Share and Enjoy.