Sour Cream (Best Option)
1:1 (1 cup sour cream per 1 cup Greek yogurt)Sour cream has a similar fat content and acidity level as Greek yogurt, which helps maintain the emulsification and body of the cream sauce. The lactic acid bacteria in sour cream provide a comparable tang that complements savory flavors.
For best results, use full-fat sour cream and add it towards the end of cooking to prevent curdling. Stir gently and avoid high heat once incorporated.
The final sauce will be nearly indistinguishable from one made with Greek yogurt, with a slightly richer mouthfeel and a mild tang that enhances depth.