I had a cheap spatula that the handle had broken off of lying around, so I decided to make up a new handle out of some oak scrap. If you want to make one just to make one, without having the broken parts already around, you could probably just go to a dollar store and get a spatula and remove its handle. If you do this, you'll want to use a clean way to cut it, and cut it at the point where you want the handle to meet the metal part.
Either way, you'll need:
The metal parts described above
A piece of wood suitable
Medium grit sandpaper
A spoke shave or two
A plow plane
A bench vise
A drill (preferably a drill press)
1/4" drill bit
5/16" threaded rod
5/16" tap (for threading the hole)
A table saw
A welding or brazing machine
Some food-safe lacquer and a clean rag
Step 1: Prepare Your Design
I used a half-centimeter grid. In the photos, there are marker marks on the spatula part, which are just different options of length. I ended up going with the shortest of the three.
Step 2: Cut the Rough Handle
Cut out the rough handle shape. On the grid paper, I just eyeballed the angle, and drew it with a pencil. I did mark those lines onto the wood to follow when cutting.
I ripped it, down the grain, one inch wide. The blank I was using was an inch thick, so the dimensions of the rough handle were 1" x 1", and 6" long.
Step 3: Carve and Sand the Handle
Using first the larger spoke shave, I just cut a rough bevel edge on all four edges, starting the cut about 1.5" from the end the metal was to be fastened. Then, I cut successively more round edges, switching to the smaller spoke shave once I felt that smaller cuts were necessary.
The sixth picture shows the shape of the end the metal was going to be threaded into. The two sides on the front that I hadn't beveled on the table saw, I used the plow plane to bevel. Then, I used the smaller spoke shave to run a small bevel on all four edges up to the end of the piece.
The fifth picture shows the handle already sanded, which I did a lot of. The sanding will be (however not too awful much) easier if you use the smaller spoke shave at the end of your carving. Near the end of the process of carving, I used more and smaller cuts. This creates a smoother round before sanding. I do not recommend deep cuts with the spoke shave, because doing so creates little nicks from the blade, which are very difficult to sand. You want a smooth, shallow cut, with one long and coiling shaving.
Step 4: Drill and Thread the Hole
I (with assistance) drilled the hole into the metal end of the handle, 1.125" deep. Then, I used the 5/16" tap to thread the hole about three quarters of the depth of the hole. Doing so leaves some un-tapped wood to be threaded by the rod on the metal part, giving it a stronger hold.
Step 5: Make the Metal End
I'm no buff on brazing and welding, but my dad is, so we agreed to make it a duo effort. He brazed on a 5/16" threaded rod, with enough extra to go into the wood about an inch. Brazing is better for this application because it uses brass, which does not have iron. Brass does not rust, and this is good for something that will be washed in water quite a lot.
Step 6: Put It All Together
Now you can just thread the two together. Depending on how deep you threaded prior, there will be some harder cranking near the end.
Step 7: Lacquer the Wood
I used two coats of a food-safe cutting board oil, which I found in the paint aisle.