|Frozen raspberries||15 Ounce, thawed|
|Sugar||1⁄4 Cup (4 tbs)|
|Lemon juice||2 Tablespoon|
Force raspberries through a sieve and discard seeds.
Mix cornstarch and sugar in a saucepan.
Stir in raspberry puree gradually.
Set over high heat and cook, stirring constantly, until mixture comes to a boil.
Remove from heat.
Add butter and stir until butter is melted.
Stir in lemon juice.