yes, it is a carrot that is cut with a flower shaped vegetable cutter. this is the one i have here: [link]
Yes you can use any meat you like. Pork and Chicken are the traditional meats used for making katsudon/chickendon
when you make this please make sure to pay very close attention to the directions. I made this sort of odd in explaining certain parts. in the ingredients it says 2 cups dashi-stock.... your actually going to make it using hon-dash + 2 cups water so just ignore that part. put soy sauce last and only add to taste because its very salty and if you add to much there is no fixing it. it is to be eaten that day and possibly the next day but no later then that. enjoy!