Soak the bihun in a bowl of warm water to soften it and then drain and set aside. Soak the atsuete in a some water to draw out the colour.
Prepare all the toppings so that it's faster to put the dish together.
To make the sauce, heat a little oil and saute the garlic, onions and prawn shells in a pot for a few minutes. Add the soaked atsuete and water and stir. Pour in 250 ml water and bring to a boil. Remove from heat and strain the stock into another pot. I know, but it's worth to make your own prawn stock.
Put the strained stock back on the heat. Add the chicken bouillon and the rest of the water in the pot. Slowly pour in the cornflour slurry while stirring to thicken the sauce. Season the sauce with patis and pepper to taste. Simmer until sauce has thicken, remove from heat and set aside.
Prepare a pot of salted boiling water. Quickly blanch the prawns until it's cooked remove and set aside.Blanch the noodles until just cooked. Drain the noodles into a colander and put noodles in a serving dish.
Pour the sauce over the noodles. Top the noodles with shredded chicken, prawns, sliced hard boiled eggs, tinapa flakes, chicharon, fried shallots and sprinkling of chopped green onions. Serve with calamansi or lime to squeeze over it for added zest.