Begin by cutting the aubergine into large cubes. Start by slicing it lengthwise twice on one side, then make one lengthwise cut on the opposite side. Finally, cut it into chunks. Place the cubed aubergine into a bowl and generously season with salt and pepper. Add three tablespoons of corn starch, ensuring it is evenly distributed. Gently toss the mixture until each piece of aubergine is thoroughly coated.
In a separate bowl, prepare the sauce by combining the ingredients. Begin by mixing the water and cornstarch until it is smooth and clump-free. Next, add the hoisin sauce, soy sauce, syrup, and vinegar. Stir the mixture until it reaches a creamy yet fluid consistency.
Next, heat some oil in a pan or wok over medium to high heat. Add the aubergine cubes and sauté for about 15 minutes, until they turn golden brown and develop some crispy bits. For the last 5 minutes, turn the heat down and cover your pan with a lid to allow them to cook gently for about 5 minutes, ensuring they are thoroughly cooked and soft.
After that, add the chopped garlic into your pan and let it roast for about 1-2 minutes on medium heat.
Reduce the heat to low and pour in the sauce, ensuring all ingredients are well-mixed and nothing has settled at the bottom of the bowl. Maybe give it one final stir before adding it to the pan. The low heat will cause the sauce to bubble and thicken. Once it reaches the desired consistency, remove the pan from the stove to prevent it from thickening too much. If the sauce becomes too thick, simply add one or two tablespoons of water and stir well. If it is too runny, let it cook a bit longer on the hot stove until it thickens to your preference.
Now, serve the aubergine with your choice of rice or Asian noodles. You can add optional ingredients such as kimchi, spring onions, carrots, sesame seeds, edamame, or even sliced cucumber for added flavor and texture. Enjoy your meal!