Add the 15 bean soup mix, seasoning packet, and vegetable broth to a crockpot.
Stir to combine.
Cover and cook on high for 4 to 5 hours, or until the beans are soft and tender.
Stir in the collard greens.
Cover and cook for an additional 30 minutes, or until the collard greens are tender.
Taste and adjust seasoning if desired.
Serve warm with cornbread or rice, if using.