Put the soft butter in a bowl. Finely chop all the fresh herbs and add them. Chop the capers and anchovies finely and add them. Finely chop the shallot and garlic and add them. Add all the other ingredients and season with pepper and salt. Mix everything together, taste, and adjust seasoning if necessary.
The butter is ready to use. You can either keep it soft or divide the butter onto 2 sheets of parchment paper, roll them up into sausages, and place them in the fridge or freezer. Once firm, you can slice it into nice round discs.
Tips
Use real dairy or dairy butter, no margarine or baking butter. That really makes a huge difference in taste! You can store the butter covered in the refrigerator for 1 week or freeze it packed.