This is the base I use to make creamy salad dressings. You may add herbs or substitute other cheeses, or go without cheese altogether. For this batch I used feta, but often use parmesan instead. This is almost completely carb-free and has decent protein and calcium. Obviously, amounts dictate calories.
1 cup Greek yogurt
1/2 cup full-fat mayonnaise
a few Tbsps half-n-half or milk
1 large clove garlic
1 tsp coarse salt
1/2 cup crumbled feta
Peel and finely chop garlic clove. On cutting board (or using mortar and pestle) combine garlic and salt and mash together to form a smooth paste. Stir in crumbled cheese (or finely shredded if using non-crumbly cheese).
If you prefer a somewhat thinner (more pourable) dressing, add half-n-half or milk by tablespoons, whisking after each addition. Go very slowly here as it can get too thin more quickly than you might imagine.
Put this dressing in a jar or squeeze bottle and refrigerate for at least two hours before serving. This will allow the flavors to meld. In the refrigerator, this will keep for at least a month. (To be honest, I've never had it around long enough to go bad, I eat it at least every other day.) This also makes a great dip for veggies or chips.
Combine yogurt, mayo, and garlic-salt paste in bowl. Whisk thoroughly to combine.