I have just done some learning on this and a question I didn't see answered was the following case:
One has a mixture of food, let's say a stew. They decided that the Ikar was the meat, and the carrots are Tofel (e.g. following the halacha in Yalkut Yosef 212:17, the carrots are just there to enhance the flavour of the meat), so they said shehakol. This therefore covers all of the vegetables as well according to the laws of Tofel and Ikar (see Yalkut Yosef 212, Shulchan Aruch O.C 212).
What happens if at various points during the dining, the person eating is going to be eating the vegetables by themselves a lot?
Example: the person sticks fork into a pile and pulls out just a carrot and eats it.
Example: the person deliberately makes up some spoonfuls composed of just carrots.
Example: the person finishes all the meat quickly, and now has just a (not tiny) quantity of carrots left, which he proceeds to eat.
In any of these cases or similar, does one need to make a boreh peri ha'adama on the vegetables?
I would guess from YY 212:18, 19 and especially 20, that this person should probably say boreh peri ha'adama from the start on the carrots, and it is not a beracha she'en tzericha, but given the wording, I am not sure. That conclusion is also questionable because it seems like Tofel and Ikar is quite a fragile halacha, i.e. some of the places where I see it applied such as 212:17 itself might fall under scrutiny if we say that he should bless on the carrots here... If every time I have a mixture of foods I separate out everything and make individual berachot, what is the point of Tofel V'Ikar, aside from the very different cases like condiments and cheese on crackers?