In a medium bowl, add softened butter, minced garlic, salt and pepper. Mash together with a fork.
Finely chop the parsley then add to the butter mixture along with a squeeze of lemon juice (about 1 teaspoon, you don't need to measure it). Mix to combine.
Spoon the mixture into the center of a large piece of plastic wrap. Fold over the plastic wrap and start rolling and shaping the butter into a log. Shape.
Chill for about 30 minutes until the butter has firmed up.
The compound butter will keep in the fridge for several weeks. Keep it in a sealed container or tightly wrapped to prevent the garlic smell from seeping into other foods.
Notes
Apart from the butter, I don't accurately measure anything in this recipe. I usually just grab a bunch of parsley and a quick squeeze of lemon juice.