Amazon has Reditainers. They come in packs of 10 or 20 and have lots of different styles. Here is your basic 3 compartment but there are more!
I just got reditainers, I like them so far.
Reditainer 3-Compartment Microwave Safe Food Container with Lid/Divided Plate/Lunch Tray with Cover, Black, 10-Pack https://www.amazon.com/dp/B00TUWF6DU/ref=cm_sw_r_awd_eRg5vbNH5QSGP