These are the templates I made - one for the face frame and drawer front, and the other for the front wall of the drawer box.

The face frame/drawer front template was based on the curve I cut into the cabinet case, and then the drawer box template was based off of that so they mated nicely.

Using the templates, I cut out pieces from 1x material and stacked them up as needed to get the necessary height. These two pieces are the top rail of the face frame. If you zoom in, you can see the pencil line from the template.

Using the stand sander belt, I trimmed the pieces flush to the pencil line. To get the inner curve, I took the top cover off the sander belt to uncover the top spindle, and then used that to get close to the line. The inner curve is the outer face of the pieces, so I left those a little heavy and chased them down with a orbital sander later.

The piece in the back is for the front wall of the drawer box, and the front piece is one of the rails from the drawer front (I think). Either way, it shows you how they look stacked up.

For the stiles on the drawer front, I used 5/4 stock and held it up to the curved rail that I had trimmed to the correct approximate length. Then I put the template over top to get the curve marked.

Some more work on the belt sander to get it close to the pencil lines. Again, I left them heavy to chase down later.

I joined the rails and stiles together with my domino jointer, using 8mmx40mm dominoes I think. I couldn't go too long with the dominoes for fear of them popping out of the face when I was cutting them in.

Bit of jump right now: for the drawer boxes, I was making them out of solid maple with a housed rabbet joint pinned with walnut dowels. For the curved drawer, I made up the drawers box with 3 parts (back and two sides) and a temporary short front piece so I could clamp it up and get it to the right dimensions. Then I held the curved piece over top of it and marked the joint with a pencil (visible in the next photo).

In order to cut the joint out for the drawer box front wall, I made up 2 different jigs, this being the first of them. This one (made from scrap I had laying around), allowed me make the first couple cuts. Biggest issue with this was eyeing up the blade angle and sneaking up on the pencil lines. I’m not sure if it’s visible in this picture or not, but I marked the center line of the drawer piece so I could flip it over and get the same approximate cut on the other side. It still took some adjusting, but it got me in the right ballpark.

Closer shot of what I was cutting out on the first jig.

This is the second jig to complete the cuts.

Close up of the piece on jig #2 before cutting it. I also added some side walls after I took this picture so I could run it through the table saw without the base coming apart.

After the cuts were made.

Top view of the finished joint. I ended up over cutting it just a stitch. Next time around I’d leave the pencil lines and chase them out by hand with a chisel.

After the side joints were cut, I ran it through the table saw to cut in a kerf for the drawer bottom.

The drawer box dry fit

Glued up and clamped. The front wall bowed in a bit with the pressure from the clamps, so I used a spreader in the middle to push it back into the correct place (using the template to get it right).

This is the drawer front being clamped up. I used a laminate trimmer/router to cut in grooves for the center panel to sit in. The center panel was made from 1/4” plywood that I kerfed on the backside to make it easier to bend.

Clamping it up was a pain in the ass. To do it again, I’d make up another jig for it to sit over top of, with the outer face facing down so I could clamp it down into position. This way worked, but it ended up skewed a bit diagonally. I was able to pull it back into position when I attached it to the drawer box, but it was just an unnecessary difficulty I’d try and avoid next time around.

After attaching the drawer front to the drawer box, I put in the slide hardware. I use Blum Movento slides with the depth adjusters (about $50 a pair from Lee Valley. They’re pricier than others, but they have a lot of adjustments to them which makes installation a lot easier). I had bought 20” slides - they were the right length for the other square drawers, but with the curve they ended up being too long because the front hardware (orange parts in the pic) had to be back further to operate properly. Instead of ordering shorter slides and delaying everything, I just put some spacer blocks on the back of the drawer to make it work (they’re never seen unless the drawer is taken out).

This is a close up of the drawer face top rail. You can see the joints in it and the grain change, but I’m painting it so it won’t matter. If I was doing stain grade work, I’d try and find quarter sawn material all from the same board if possible to minimize grain change and color differences.

This is the inside of the drawer box where you can see all the layers stacked up. This isn’t getting painted, but since it’s the inside front of the drawer I wasn't too concerned about it being seen.

Top view of the rabbet joint. I had to fit in some little shims to close up a couple gaps. This was the result of taking too much off on the table saw, and if I’d snuck up on it with a chisel I probably could’ve gotten a better looking joint.

One thing to note, the front wall of the drawer box is about 3/4” thick, whereas the sides are 9/16” thick. The sides have to be 5/8” thick or less for the drawer slides I was using, and I had initially thought I’d just sand the front wall down to 9/16” as well. However, when I marked the joint, I realized I couldn't go any thinner than 3/4” or the joint wouldn't work right. It’s annoying that they’re different, but this could probably be avoided by using a different joint entirely. Dovetails would probably work okay with two pieces the same thickness, but I’d have to experiment with it to be sure. I started using this pinned rabbet joint a while back because it’s a lot faster to make in the shop and people like the walnut/maple contrast so I just instinctively used it again on this project, not realizing it was going to cause this issue later on. Again, not a big deal, just sort of annoying although I’d be shocked if anyone ever noticed it besides me.

Normally I pack out the inner side walls of my cases to line up exactly with my face frames and then attach the slides to the pack outs. In this case, the side walls of the case are not at the correct angle to make that work, so I glued up some 1x stock and made this little side supports. The vertical bit in the back provides extra pressure to keep the back of the side supports from lifting up when the drawer is fully extended. The side supports are glued and tacked down, but I didn’t want to rely on just that.

One pain with this method was making sure the slides were parallel the whole time so they’d operate properly. Since this is a center unit flanked by other parts of the banquette, I could cut access holes in the side of the case to allow me to see inside and mark things with a pencil while moving the drawer in and out. I don’t think that’ll work for your project since I imagine the piece you’re making will be a stand-alone one, but you might want to consider mounting any hardware like this before you put the sides together. That way you could see everything you need to see and have it all set before putting the rest of the case together.