MY 2 YAER OLD HAS GONE OFF MOST FOOD?

my daughter is a normal healthy happy 2 year old from her starting on solids she has loved foods like potato & bread but for the last few month she has totally gone off them if i give her a sandwich she will eat the filling and leave the bread and she will not suffer to eat toast or mashed potato , she loves pasta and cheese and spagettii hoops ..... if we go for a carvery she will eat a piece of meat and thats it .... can any1 give me a little advice on how to get her to eat a little of what she doesnt seem to like