Soften gelatin as directed on package in cold water OR, as in the case of gelatin sheets, place them in a bowl with lots of cold water.
Blend strawberries, sugar and the lemon juice, juice in a blender until very smooth, then pour it in a bowl.
In the other bowl whip cream until solid.
Heat gelatin over low heat in a small saucepan, stirring until dissolved (in case you are using sheets, squeeze them by hand before you put it in the saucepan).
Remove from heat and add to strawberry mixture, then add cream and whisk it into strawberry purée. Pour into mold. Be delicate but fast in order to prevent roping (making strings of gelatin).
Pour into the mold and let it cool in the refrigerator for at least 4 hours.
To unmold, dip mold in a bowl of hot water 2 or 3 seconds, then invert panna cotta onto dessert plate and remove mold.
You can add wild strawberries in the central hole.