Cut stem ends off chilies and slice in half lengthwise. Scoop out seeds and membranes and finely mince

Remove leaves from cilantro stems and finely mince

Whisk the eggs yolks and lemon juice into the top of a double boiler and set over simmering water

Whisking constantly, slowly add the hot melted butter

As the sauce thickens you may add the butter faster

When all the butter has been added and the sauce is thick and creamy, remove from heat and stir in the chilies and cilantro

Season to taste with salt and pepper

Serve immediately or place in a thermos to keep warm for several hours.