Step 1: Prepare the Spice Paste. Begin by draining the soaked red chillies and placing them in a blender along with the ginger, shallots, ground coriander, fennel, cumin, and turmeric. Blend until you achieve a smooth paste, adding a bit of water if necessary to help with blending.
Step 2: Cook the Broth. In a large pot, heat the cooking oil over medium heat. Add the cinnamon stick and the spice paste from Step 1. Sauté for about 5-7 minutes until fragrant, stirring frequently to prevent sticking.
Step 3: Add the Sweet Potatoes and Stocks. Stir in the mashed sweet potatoes, chicken stock, and prawn stock. Bring the mixture to a gentle simmer. Add in the tamarind concentrate and coconut milk, stirring well to combine. Season with salt to taste. Allow the broth to simmer for about 15-20 minutes.
Step 4: Prepare the Noodles. While the broth is simmering, prepare your yellow noodles according to package instructions. Once cooked, drain and set aside.
Step 5: Assemble the Mee Rebus. To serve, place a portion of the blanched noodles in a bowl. Ladle the hot gravy over the noodles generously.
Step 6: Add Toppings. Top the Mee Rebus with blanched beansprouts, halved hard-boiled eggs, sliced fried beancurd, prawn fritters, fried shallots, and a sprinkle of shredded lettuce. Serve with lime wedges on the side for squeezing over the dish.