Cook pasta according to directions on package, depending on type of pasta. Make sure to add salt to the water for best results.
Drain pasta, but do not rinse! Reserve some pasta cooking water.
In the same pot you cooked the pasta, melt butter over medium heat until melted.
Add minced garlic and cook for 1-2 minutes until garlic is fragrant, but not brown.
Turn heat to low and add yogurt, stirring to blend. Toss in pasta, stirring to coat pasta. Add reserved pasta water to thin sauce if necessary, 1 Tablespoon at a time.
Add zest and juice of half a lemon and salt and pepper to taste.
Serve with grated cheese and fresh parsley or chives.