Add the butter, a couple of pieces at a time.
It should not be necessary to add additional butter or oil.
That's probably why you have to add the extra butter.
Return the pan to the heat and add the butter.
For the best taste, don't add the butter until just before serving.
Then turn down the heat, add a little olive oil or butter, and cook for another 5-10 minutes.
Add the butter and remove the pan from the heat.
Break the chocolate into small pieces and add the butter.
Add butter and process for 10 seconds, until well blended.
Add the butter to the pan and place in the oven.