Charles Hall started out by sailing a small dinghy on the local lake, and he has now completed a single-handed yacht journey around the world. (Advanced Grammar in Use (2nd edition), Martin Hewings) Can we omit "by" with no difference in meaning? It sounds OK to me. Thank you in advance.
Charles Hall started out sailing a small dinghy on the local lake. This is more likely. It means that this is what he did when he started out. Charles Hall started out by sailing a small dinghy on the local lake. This means that he sailed a small dinghy on the local lake as his chosen method of starting out. The difference isn't very clear in this case. Here are some other examples: He came into the room whistling. This is what he was doing when he came into the room. He got into the room by breaking the lock. This is what he did in order to get into the room.
In your example Tomato, yes, you can eliminate the by with no change in meaning. In fact, I think it is preferable in this text. However, you cannot always eliminate the "by" in similar uses without changing the meaning. For example: To make pizza, he started out by kneading the dough. Then he rolled it out... etc. I personally use "by" when I'm talking about how a person is beginning a long process, such as making pizza, but not in a case where the person started out his career in a certain way. He started out washing dishes and later was promoted to making pizza.
