Prepare the Baking Sheet: Line a baking sheet with parchment paper, ensuring it's smooth and easily removable.
Melt the Dark Chocolate: Place 1 cup of dark chocolate chips in a microwave-safe bowl. Microwave in 30-second intervals, stirring in between, until fully melted and smooth.
Spread the Dark Chocolate: Pour the melted dark chocolate onto the lined baking sheet, using a spatula to spread it evenly into a rectangle about 1/4 inch thick.
Melt the Milk Chocolate: In another bowl, melt the milk chocolate chips using the same method as the dark chocolate until smooth.
Drizzle the Milk Chocolate: Spoon the melted milk chocolate over the dark chocolate layer in a zigzag pattern. Use a toothpick or knife to swirl the two chocolates together for a marbled effect.
Add Strawberries and Nuts: Quickly sprinkle the crushed freeze-dried strawberries and chopped nuts (if using) over the chocolate before it sets.
Garnish with Sea Salt: Lightly sprinkle a pinch of sea salt over the top to enhance the flavor.
Chill to Set: Place the baking sheet in the refrigerator for about 30-45 minutes or until the chocolate is completely set.
Break into Pieces: Once set, remove the chocolate bark from the baking sheet. Using your hands, break it into irregular pieces for a rustic look.