[rwest]

I just had a similar issue; had a full panel, but needed to add a 240v outlet for an electric oven.

I went through my panel and found breakers with low loads on them and then took two circuits, wire nutted them together, and ran a pigtail to the single breaker- code allowed this; you can’t put both wires under the breaker screw, but using the pigtail made it fine.

Doing this to four circuits opened up a double space for the 240v appliance.

Keep in mind that the code does insist that certain items have their own breaker (kitchens have many) and sometimes special breakers like arc fault and or ground fault, so you have to make sure the circuits you double up can be together.

I think I did things like putting basement and bedroom lights on one and two different sets of outlets together.

My work was inspected, but I’m in MN, so might be different where you are.