You can make a pouch type sheath. Not sure if that’s the correct term. But you more or less tape the blade up. Then wet the the leather and press it tightly against the knife with it wrapping  the spine.  Trim and stitch or vice versa. It’s more or less just a pocket for the blade and ones I’ve seen only go maybe 1/4-1/2 up the handle. There is no belt loop or fasteners to hold the blade in. Hence the the wet and formed leather. Some have also been a mere tapering without the forming. It would also depend on the blade shape whether this type would work for you.  
could also try using a Kydex or the like liner formed to the blade then use adhesive to affix leather then lace it to give a more regal look to a thermoformed plastic sheath. For this I like deerskin as it’s a soft pliable hide and stays soft even after wetting. Be careful of steep angles with this process as bonding in corners or sudden directional changes may be problematic. With most kitchen knives they are wider and flatter so not really an issue. 

Well that’s what I got offhand. Hope it helps

I've only done it once for a kitchen knife, but I made basically a leather saya or frog sheath without the stud/sam brown. I didn't use any sort of retention system because the sheath was snug and I wanted to keep it simple. It might look and function well with a typical sam brown button and leather strap to retain the blade. The only problem I see with leather and carbon steel knives is customer's not properly drying there blades. I've serviced some knives from professional chefs that were infuriating. 

If the blade is not stainless, I think a sheath is a bad idea for a kitchen or chef's knife. Rust will form when moisture is in close contact and a sheath is a perfect way to make that happen. I provide a very simple stand for my kitchen knives. It keeps the knife dry and within easy grasp on the counter top. It also functions as a small cutting board when needed.

@joshua-c-states I am thinking the leather would be for travel or presentation. Some folks like to take their knives with them on vacation, parties, whatever. I agree that leather for long term storage would be a bad idea. I have thought about making a wooden wall magnet for at home use. I want one for my house but not until the kids get older. Little animals would find a way to get them if displayed.

@thomas-franklin I clearly misunderstood the question. I thought it was intended for something to keep it in when storing in a drawer. (something I generally discourage) For a travel sheath on a chef knife, I have made very simple leather sheaths. They are two pieces of leather shaped the same as the blade with about 3/16" extra around the perimeter for a welt and stitching. Use a thin welt, like 4/5 oz. or whatever is about the thickness of the blade spine or a little less. It is just to keep the edge from cutting the stitches. It would naturally be tight fitting because of the limited space between the sides. 

Maybe light weight leather and doing a wrap and tie shut? Like  a 3 layer fold-over. That would be simple and elegant. Not meant to carry, but could safely go in a briefcase or whatever for transport, and look organized and elegant in a drawer. Just make a little pocket in the center fold for the blade tip to sit into and, wrap it up like a button wallet or something. I might try that on my next one 🙂 

That would use a lot of leather, but it would be light weight so not that expensive, and should be pretty easy to make.

I make a simple leather Edge Protector "sheath" for my Kitchen Knives - as seen here. The primary intent is to protect the edge from damage and the user from getting cut when transporting them. I always suggest that my buyers store the knife in a knife block or on a magnetic knife strip.