Step 1: Line a baking sheet with parchment paper or a silicone baking mat. Slice your strawberries and banana thinly. Lightly brush the banana slices with lemon juice.
Step 2: In a microwave-safe bowl, melt the dark chocolate in 30-second intervals, stirring in between, until completely smooth.
Step 3: Pour the melted chocolate onto the prepared baking sheet and spread it with a spatula into an even layer, about 1/4 inch thick.
Step 4: Warm the peanut butter in the microwave for 15-20 seconds. Drizzle it over the wet chocolate in a zigzag pattern.
Step 5: Evenly arrange the sliced strawberries and bananas over the chocolate and peanut butter. Sprinkle with chopped peanuts and a pinch of flaky sea salt.
Step 6: Place the baking sheet in the refrigerator for 1 hour (or freezer for 30 minutes) until the chocolate is completely set and hard.
Step 7: Remove from the fridge, break the bark into pieces with your hands, and enjoy immediately! Store leftovers in the fridge for up to 3 days, or in the freezer for up to 1 month.