In a small mixing bowl, mix together the sliced strawberries and sugar. Then cover and set aside for 20 minutes on the counter. Alternatively, you can store them this way in the refrigerator for up to 24 hours.
Once the strawberries have set for at least 20 minutes or longer, they should have produced a lot of juice; this process is called "maceration." Go ahead and dump them into a mesh strainer over another bowl so that you can save these juices for a later step. Then use a rubber spatula to stir the strawberries around in the strainer, squeezing out any juice you can from the strawberries. Let them set over the bowl to drip out some more while you move on to the next step.
In another large mixing bowl, whisk together the Jello mix and boiling water, whisking for 2-3 minutes, or 'til the Jello mix is completely dissolved.
Next, pour the strawberry juice into a 2-cup measuring cup, making sure to scrape the sides of the bowl out into the juice. Then finish filling it up the rest of the way with cold water until it reaches the 2-cup mark.
Stir this strawberry juice mixture into the Jello, whisking everything together until blended together.
Finally, dump your strawberries into the Jello solution, and mix everything together 'til the berries are well distributed throughout the mixture.
Cover with plastic wrap, and chill in the refrigerator for at least 4 hours, preferably overnight.
Once your Jello is slightly soft but still firm, this means that it's fully set and ready to serve. Enjoy this easy and delicious no bake dessert at any potluck, family get-together or holiday dinner!