I've been stewing over the problem for a while.

这个问题我已经考虑了一会儿。

If the innards of each pig are Petri dishes, then possible pandemic flu viruses have been stewing on hog farms for decades.

如果每头猪的内脏都是培养皿，那么可能的大流行性流感病毒已经在养猪场熬了几十年了。

Stewing meat for supper.

晚餐吃炖肉。

I am almost 56 hours of stewing.

我差不多炖了五六个小时。

This is what I call stewing in your own juice.

你这叫做自作自受，没人可怜你。