Tomater, creme fraiche

Name: Varm barbecuesås
Prep time: PTM15
Cook time: PTM0
Total time: PTM15
Yield: 4
Ingredients: 1 gul lök; 2 vitlöksklyftor; 1 msk smör; ½ burk krossade tomater, á 400 g; 2 dl crème fraiche paprika och chili; 3/4 tsk salt