2. Melt 1 tsp butter in a skillet over medium-high heat until the butter foams; saute capers, about 15-20 seconds. Add lemon juice, bring to a simmer, stirring frequently, until the liquid is reduced by 1/3, approximately 2-3 minutes. Season with salt and pepper. Remove from heat.
3. Stir cold butter into lemon mixture, stirring constantly until butter is melted and thick.