For the lemon thyme butter, bring the butter to room temperature and blend briefly in a food processor or with a hand mixer until smooth.
Finely chop the thyme and lemon balm, squeeze the lemon and grate the zest. Stir in thyme, lemon balm, lemon zest and juice.
Season to taste with salt and pepper, pour into a mold and place the lemon thyme butter in the refrigerator to set.