Cut offs were clamped in place to show the "before" state.
I've been confronted with this type of thing many times, tight conditions, you can't take it into the shop, no small plunge cut saw, etc. And you don't want a huge mess because you're working in a lived-in area. In this case, the kitchen. I always start with the intent of making a "shop quality" cut and that's usually where the quandary begins.
I have routers, 6" & 7" circular saws, a jig saw, a couple Japanese hand saws, forstner bits, drills, etc. The circular saws were out. Too big, bulky and messy. Trying to rout through quarter-century old oak didn't work for me either. So I did the top and bottom crosscuts with a Kataba saw and the rips with the jig saw. The jig saw cut was less than perfect. I sanded to the line to finish it off. And still had a huge mess that, in total, took me almost an hour to clean up, even with tarps laid out. The tiny chips ejected much farther than I expected.
So I was wondering how you guys tackle a job like this? Keeping in mind a good quality end result and not too big a mess.