Christina's Chicken Alfredo

1/2 TBSP olive oil
1/4 large onion, diced
3 boneless, skinless chicken breasts, cut into thin strips
1/2 C milk
1/2 C sour cream
1 tsp (rounded) dried basil leaves
Dash of garlic powder
6 oz cream cheese, cubed
1 package linguine or fettucine, uncooked
1/2 grated Parmesan cheese

Heat oil in large skillet over medium heat. Add onion and chicken and cook until onions are soft and chicken gently browned, about 8 minutes. Stir in milk, sour cream and basil. Heat to just boiling, then reduce heat and add cream cheese, stirring until cream cheese melts and sauce is smooth. Reduce heat to low. In a saucepan, cook pasta and drain. Stir Parmesan cheese into sauce and then toss with pasta. Serve immediately.