Smashed New Potatoes with Fresh Herbs

Name: Smashed New Potatoes with Fresh Herbs
Ingredients: 2 pounds new potatoes (red, yellow and purple are pictured); 2 green onions (trimmed); 4 large leaves fresh sage; 4 large sprigs fresh Italian parsley; 8 sprigs fresh thyme (leaves removed from stem); 1/2 cup plain Greek yogurt; 2 tablespoons softened butter; 1/2 teaspoon kosher salt (or to taste); Freshly ground pepper to taste