khao soy is basically a Thai soup, right?
Have you heard of Kai Chai? It's basically Chinese fried chicken wings. You could take chicken wings.....marindade them in Asian seasoning....and fry golden-brown. They'll go nicely with soup. And you can make dumplings (either steamed or fried)....since the chicken wings would be fried.......steamed dumplings would provide a different texture. So that's three appetizers (soup, chicken wings, dumplings).
Or do you want to make your theme Southeast Asian dishes. In that case how about making sushi one of your appetizers. I remember you like sushi. So.......you can have three appetizers: soup, sushi, and some sort of fried treat.
Deserts.......hmm..........from what cuisine?
Crispy rice-flour fried bananas with a scoop of ice cream are often served in SE Asian restaurants. It provides a lovely texture with the ice cream. That's something a bit different.
Tiramisu?
Souffle?
Mixed Pastries: Baklava, eclairs, napolean
Puddings
Cakes
Kulfi
Brownie a la mode
Chocolate fondue.......with various dipping treats (an assorment of fruit, cookies, marshmallows, pretzels, and bread).....this will go nicely with chai or coffee at the end of the meal.