Preheat oven to 400 degrees F (200 degrees C).
Toss the Russet Potato (2) in Olive Oil (1 tablespoon) and lay them out on a baking tray, then bake for 30 minutes.
A few minutes before the potatoes are done, prepare the sambal sauce: Put Red Chili Pepper (2), Garlic (3 clove), Shallot (3), the pale part of the Lemongrass (1 stalk), Ketchup (1 tablespoon), juice from the Lime (1/2) and Water (1/4 cup) in a food processor or Magic Bullet and blend till smooth.
When the potatoes are ready, heat up Cooking Oil (1 tablespoon) over medium-high heat in a wok or frying pan. Pour the sambal into the wok. Fry until most of the water evaporates and it starts to thicken up.
Add Granulated Sugar (1 tablespoon) then stir to dissolve. Add the potatoes. Stir to coat all of the potato cubes with sambal.
Add Kaffir Lime Leaf (1) and stir to combine before turning off the heat.
Enjoy warm as a side dish, alone as a snack or over some steamed white rice.