It's hard to tell exactly what goes wrong here—or even if anything goes wrong. For one thing, there appears to have been some miscommunication about exactly what ingredients she'd need: She has no idea what kind of oil they're using; the beans were meant to be refried, not whole black beans; the onion is a complete mystery to her. Secondly, and perhaps more crucially, uh, it sure as hell seems like Eva Longoria has never cooked this recipe before in her life.
But hey! She's charmingly laid-back about the whole thing, handles it with aplomb, and, what the hell, the finished product probably tastes OK. God, I'll eat anything. What the hell.