1/2 cup full-fat sour cream
1/2 cup buttermilk
1 1/2 ounces blue cheese, crumbled (1/4 cup)
1 tablespoon red wine vinegar
Combine everything except the salt in a blender and puree until very smooth. Season the mixture with salt and pour it into the canister of a 0.5L whipper. Charge the whipper with one cream (N20) cartridge. Shake the siphon and refrigerate until well chilled, 30 minutes.