Name That Drama: Bags and bags of Subway sandwiches

I’m looking for the name of a drama where the male lead is a doctor, who was raised in an orphanage, and he’s been looking for his younger sister. He meets his sister and I think he becomes her mentor, but never tells her that he’s her brother (which causes some conflict later). The thing I remember most is the Subway PPL. When the adult brother and sister visit the orphanage they grew up in, they bring bags and bags of Subway sandwiches for the kids. (How is this my most vivid memory? Good job, Subway.) Anyone know what this drama is? It would be pre-2019.