- Cook pasta. Meanwhile, melt butter in a large saute pan over medium heat. Add garlic and cook until fragrant, about 2 minutes. Whisk in flour. Gradually whisk in broth, milk, and cream. Cook, stirring frequently, until sauce is thickened. Add cheese and cook and stir until melted and smooth. Add vegetable stock. and cooked pasta. Toss to combine. Season with salt and pepper, to taste. Stir in parsley just before serving.