Unicorns mostly eat grass and leaves; similar to horses. But they also like treats. Their favourite treats are Maoams, pashmak, butter icing, ice-blocks and Roses chocolates. They also like sushi, and zereshk-polo mixed with adas-polo. (As you know, polo is a type of rice.) With the polo they like potato-tadig.
Oh, I forgot, fruit. Unicorns love fruit! Particularly apples, pears, carrots and watermelons. They also love berries – all kinds of berries, and cherries, too.
Really, unicorns love all kinds of healthy foods but they never EVER eat junk food, particularly not McDonalds. Unicorns hate McDonalds.