He likes fish very much,but my favourite is ________(tomato).是填tomatoes还是tomato?为什么

My favourite food
Everybody has his/her favourite food,such as icecream,apples,or something else.But my favourite food is special---chocolate.
Why do I like chocolate? Because its taste. When you first you taste it,it's bitter.But then you keep it in your mouth for a moment,it's sweet!
That's fantastic!And that's why I love it.Life is like chocolate,first you taste it,it's bitter,but it will taste sweet through your hard work!I love chocolate very much!

tomato,
is后面用单数

应该是tomato吧
首先西红柿可属
favourite后面是is,单数,所以应该填
tomato
不知道对不对,只是这样认为的
PS:嗯,好像这种情况一般都是复数啊!

tomato。 除非你说， ... but i like all kind of tomatoes.