thanks for the tips.
the wood is about 26mm thick and i don't have a scroll saw. The slab of wood may be to big as it's about 2200mm x 600mm x 26mm . I think i might go at the short cuts with the jigsaw then work my way from there!
It helps out if you fill out your profile with listing tools you have so that others can recommend techniques geared to what you have... Otherwise we're guessing what your have and reaching by throwing out guestamations. I held off a bit until I could get a feel of what you had and your skill level.
Realistically, the easiest way I can think of doing that would be to lay out the saw marks... I would then ruff cut it out with a circular saw. If you aren't familiar with an inside blind cut with a circular saw... It is a not a technique for the light-hearted and needs practoce to do it safely and accurately.
What you do-- You position the saw over the where the blind cut will be, Youlay the leading edge down onto the work with the trailing edge lifted off the work. You rotate the gaurd back and hold it there, so it exposes the blade. you hold the saw with the blade just off the work as you start the saw with the blade off the work. You lower the lifted trailing edge until the blade slowly cuts through the edge and the balde is through the work piece.the top of the cut will be from inside corner to inside corner. You then cut the cuts from the edges to those inside corners.
The underside of the cuts will not be to the corners. They will be cut short of the corners. I finish those off with a saber saw, jig saw, pull saw or crosscut saw.
If the length of the cut will be short, adjust the blade on your saw up so it just gets through the material. On small cuts, like in cabinets, siding, paneling, etc, we usually use a smaller diameter bladed saw such as a 5-1/2" circular saw of double-cut kick saw.
If all you have is hand tools, then drill pilot holes near/inside the corners to get a saw cut started on your indie cuts and reverse directions to get clean cuts into the corners.
On getting a clean finish cut on hardwoods, before you lay it out, put down blue masking tape, lay it out, then score the line with a knife. Cutting through the surface grain. you'll cut without appreciable tearout of the surface fibers. If you need support for the cut to get a straighter line, clamp pieces of wood to help you guide your saw.
Sorry for the guesses, but the best I could do on the info given.