Go to Saffron in Tienmu, The husband goes there all the time is his suit, with other suits and dresses. Its Indian, you can go there in khakis or suits it doesn’t matter and a good meal for 2 will end up being 2000 or 2500. SO that’s in your budget. You will have to commute though. Call in advance make a reservation.
Even though the place is very very small, the food is classy.
I am surprised no one mentioned DIY yet. As in get the food catered, light up a candle at home, dress up and open a bubbly!