For a milder citrus flavor, you can replace part of the lemon juice with orange juice—try 1/4 cup lemon juice and 1/4 cup orange juice for a softer, sweeter taste. If you enjoy a little texture, sprinkle 1–2 tablespoons of shredded sweetened coconut over the pastry before pouring on the lemon mixture. To add a berry twist, scatter 1 cup of frozen blueberries or sliced strawberries over the frozen puff pastry, then pour the lemon mixture on top; the berries will cook down into little pockets of jammy fruit. For a richer flavor, you can stir 1 teaspoon of vanilla extract into the lemon mixture. If you prefer individual portions, you can prepare this in well-greased heatproof ramekins set into a larger slow cooker with a bit of water around them, though timing may be slightly shorter. Food safety tips: Always keep the puff pastry frozen until you’re ready to use it so it handles well and stays safe; do not leave it sitting at room temperature for long. Use pasteurized sweetened condensed milk and freshly squeezed, well-washed lemons. Cook on LOW, not on the “warm” setting, to ensure the custard heats through safely. Leftovers should be cooled to room temperature within 1–2 hours, then covered and refrigerated; enjoy within 2–3 days, reheating gently in the microwave or enjoying cold.