Mash butter in a small bowl with the back of a spoon until soft and creamy. Stir in oil until combined. Add chives (or shallot), capers, marjoram (or oregano), lemon zest, lemon juice, salt and pepper. Cover and place in the freezer to chill.
MAKE AHEAD TIP;.
Can be wrapped in plastic wrap and kept in freezer for up to one month.