Wash strawberries and pat dry. Remove tops and chop, then add to a saucepan. Add the sugar and lemon juice and stir.
Set over medium heat and bring to a simmer, stirring to dissolve sugar. Cook 5-10 minutes, until berries are softened and very juicy. (If mixture is too bubbly, reduce heat to medium low.)
Remove from heat and pour into a blender. Purée until smooth. If desired, pour through a fine mesh sieve to remove seeds.
Transfer to an airtight container and let cool slightly before serving, or chill. The coulis will thicken slightly as it cools, but should still be very pourable. Serve over your favorite breakfast or dessert dishes.