The motzi

I used to think people said ha motzi before every meal, no exceptions. I thought it was strange considering it thanks the creator of bread, specifically (what if there is no bread in the meal… like someone eating a keto meal?)

Then someone told me you say a prayer for whatever is the main focus of the meal (like if you’re a vegetarian, you’re probably going to say boreh pre ha’adama.)

Is this true? Does one actually have to make a conscious decision over which is the most appropriate prayer to say for every given meal?

And what about the birkat hamazon? Who noten lechem lechol basar. What if I don’t eat lechem? Do I still say birkat hamazon?