Preheat oven to 350 degrees.
Toss sliced strawberries with 1 tablespoon sugar, then spread them on a parchment paper- lined baking sheet.
Roast strawberries for 10-15 minutes, until they are bubbly and beginning to darken.
In a small saucepan, combine water and sugar. Bring to a boil, then stir to dissolve the sugar.
Reduce to a simmer.
Add roasted strawberries and their juice to the water and sugar mixture.
Remove pan from heat and let strawberries steep for 30 minutes.
Strain through a fine mesh strainer.
Refrigerate until well chilled.