To begin, rinse the jasmine rice until the water runs clear. In a pot, combine rice, coconut milk, salt, bay leaves, and lemongrass. Cook over medium heat, stirring occasionally, until the liquid is absorbed and the rice is half cooked. Set aside and cover with a clean towel while you prepare the filling.
In a pan, heat the oil over medium heat. Add minced shallots, garlic, and chillies. Sauté until fragrant and slightly golden. Proceed to add the vegetables.
Add diced tempeh and carrots to the pan. Stir well to combine with the aromatics. Season with sweet soy sauce, salt, and sugar. Cook until the mixture is dry and flavours are well blended, about 5–7 minutes. Set aside to cool before assembling.
Briefly pass banana leaves over an open flame or hot pan to soften them. Wipe clean and cut into rectangles. This step ensures they fold without cracking. Ready your wrapping station next.
Take a banana leaf and spread a thin layer of the half cooked rice in the centre. Flatten it into a rectangle. Spoon a generous amount of filling across the middle, then cover with another layer of rice. Compact gently with damp fingers.
Fold the sides of the banana leaf over the rice to form a tight roll. Tuck in the ends and secure with toothpicks. Repeat with the remaining rice and filling. Transition to steaming next.
Place the wrapped parcels in a steamer basket. Steam over medium heat for 45 minutes, or until the rice is fully cooked and the banana leaves have darkened. Turn off the heat and let rest for 10 minutes.
Allow the parcels to cool slightly before unwrapping. The rice will firm up and hold its shape. Transition to plating.
Serve Arem-Arem warm or at room temperature. It's perfect on its own or accompanied by a mild chilli sauce. For added texture, pair with prawn crackers or fresh cucumber slices.