1. Line an 8-inch square pan with non-stick tin foil or parchment paper, or regular tin foil sprayed lightly with baking spray.
2. Pour the white chocolate chips and key lime curd into a microwave-safe mixing bowl.
3. Heat at 70% power for 90 seconds.
4. Let the bowl rest in the microwave for 3 minutes.
5. Remove and stir until melted. If needed, heat for another 15 seconds at 70% power. Let rest, allowing the residual heat in the fudge to melt any remaining chips, then stir until melted.
6. Spread the fudge into the lined baking pan.
7. Cover the pan with a piece of tin foil or plastic wrap.
8. Chill in the refrigerator for about 3 hours until firm.
9. Remove the fudge from the pan and peel off the tin foil or parchment paper.
10. Cut into 36 squares and enjoy!