In a saucepan, heat the olive oil and butter. Add the mushrooms.
Cook till it starts wilting and releases fluid. Add the garlic and basil and continue to cook for around 5 minutes till done.
Add the cream along with seasoning and give a good mix.
Whisk the cornflour into the milk and pour into the mixture. Mix well till the sauce thickens.
Add the remaining ingredients and switch off. Adjust seasoning.
Serve warm with mashed potatoes and fried chicken on the side.
Notes
Instead of basil, you can use thyme or rosemary. I used what I had in my pantry. If you have parmesan cheese in your pantry, you can add that at the end before switching off and just till melted.