Penne Jamur Sederhana dengan Pesto Walnut

Bahan-bahan (4 porsi)

• 8 ounces penne pasta
• 4 tablespoons butter
• 16 ounces fresh sliced mushrooms
• 1/4 cup grated or shaved Parmesan cheese
• salt and pepper, to taste
• 1/4 cup fresh parsley, for topping
• 1 cup walnuts
• 1 1/2 cups packed greens (spinach or basil are great – but keep some basil for a more traditional pesto flavor)
• 1/2 to 3/4 cup shredded Parmesan cheese
• 1/4 cup olive oil
• 1 clove garlic
• juice of 1 lemon
• salt and pepper to taste