Saute the onions in olive oil in a heavy skillet until they are translucent. Scoop the peanut butter (I'd say four or so tablespoons is reasonable, but I'm sure you could use less and it would be fine) into the pan. Mix in the tomato sauce and about half the syrup from thecan of yams. Mix in the cayenne and curry powder if you plan to use them. Stir the sauce, making sure to break up the peanut butter globs. As the sauce seems to be heating up, put the collard greens into the skillet. Keep heating the greens until they are somewhat soft. Then add the yams and both cans of beans. Stir until everything is well coated with sauce and the flavor seems delicious! It's nice to serve this dish over rice or the grain of your choice.