4 center-cut beef marrow bones, cut lengthwise by your butcher
1 tablespoon plus 1½ cups softened unsalted butter
3 tablespoons minced shallots
2 tablespoons minced Meyer lemon (with skin on)
2 tablespoons finely chopped chives
2 tablespoons minced parsley
¼ teaspoon sea salt
⅛ teaspoon red pepper flakes
1. Preheat oven to 350°. Place the bones on a baking sheet lined with aluminum foil and roast until marrow is just soft, about 15 minutes. Allow to cool.
2. Meanwhile, heat a skillet over medium heat. Melt 1 tablespoon of the butter, then add the shallots and cook, stirring with a wooden spoon, until softened, about 4 minutes. Transfer the shallots to the bowl of a standing mixer fitted with a whisk attachment.
3. Using a small spoon, remove the marrow from the bones and add to the mixer along with the remaining butter, Meyer lemon, chives, parsley, salt and red pepper flakes. Whip on medium-high speed until the butter is incorporated and fluffy.
4. Using a rubber spatula, mound the butter onto a piece of parchment paper and roll it to form a cylinder. Twist the ends of the cylinder like a party favor, then chill until firm, about 1 hour. To serve, slice the butter into rounds and place a round on top of a steak to melt.