Add oil and garlic to a cold medium-size skillet. Turn heat to low and lightly simmer for 10-12 minutes, until softened. The oil should be just lightly bubbling – do not let garlic darken in color. It's very important to not rush this – go "low and slow".

Add the anchovies and stir to combine, still over low heat. After 1 minute, use a wooden spoon to break up the anchovies. They will start to literally melt into the hot oil and garlic, and should be completely broken down in about 5 minutes.

Add butter and stir occasionally, until completely melted and combined. Then simmer for 1 more minute over low heat.

Transfer finished bagna cauda to a small fondue pot, with a lit candle beneath. Serve with chunks of crusty Italian bread and fresh vegetables, to mop up the savory sauce.