Roast the beans in the oven in a large flat Pyrex baking dish so that the flavors in the chocolate are developed and the husks separate easily from the nibs. Start the oven at 350°F for 10 minutes, 300°F for 10 minutes, and then 250°F for 10 minutes. Turn them every 5 minutes and leave the oven door open in between each temperature setting for a minute or two to bring the temperature down.
Most chocolate makers do this by smell rather than by following strict times. When you lose the vinegary smell and begin to enjoy the aroma of a cross between freshly mown hay and chocolate brownies and you hear a bean or two pop, the beans are done. This step also kills any microorganisms on the beans. (Do you really want to eat something that has been lying on the ground in a tropical country without sterilizing it?). The beans then need to cool for a few hours, preferably overnight, so the flavor can develop further. Just leave them on the counter in the baking dish to cool.