In a medium saucepan, combine cream, sugar, lemon zest and salt over medium-high heat. Bring to simmer, stirring frequently to dissolve sugar. Simmer vigorously until mixture thickens slightly, about 4 to 5 minutes.Remove from heat and stir in lemon juice. Let sit until mixture has cooled slightly and a skin forms on top, about 20 minutes.Stir mixture, then strain through fine-mesh strainer into a measuring cup with a spout; discard zest. Pour mixture evenly into six 6-ounce ramekins or small bowls.Refrigerate, uncovered, until set, at least 3 hours.As the custards chill, prepare the strawberry topping: Toss strawberries and sugar in a small mixing bowl. Let fruit macerate at room temperature for 30 minutes to 1 hour, until the sugar is dissolved.To serve, top each lemon custard with some strawberry topping and grind black pepper on top.