Wash and dry the green beans. Cut the ends of the green beans on both sides.

Add olive oil to a medium-size skillet.

Warm the pan to medium heat until the oil is shimmering.

Stir in the butter.

Add the green beans to the pan and spread them out in the pan.

Cook the green beans, stirring occasionally, until soft and starting to blister. (Note, they will also start to turn black in spots and that is perfectly fine.)

The green beans are done when they turn bright green. 

Remove the pan and season with salt and pepper to taste.