6 small (about 1-1/2 pounds) russet potatoes, peeled and quartered
3 medium parsnips (about 1 pound), peeled, cut into 2-inch lengths, large ends cut again in half to cook evenly
1/2 cup half-and-half or milk
3 Tablespoons butter, or more to taste
2 Tablespoons fresh herbs (optional)
Kosher salt and freshly ground black pepper
Gently reheat over low heat, if necessary, before serving.
8 to 10 servings