Making Jajangmyeon at home is simple when you follow these clear steps:

1. Cook the Noodles: Boil a pot of water and cook the Jajangmyeon noodles according to package instructions. Drain and set aside.
2. Prepare the Sauce: In a large pan, heat vegetable oil over medium heat. Add diced pork belly or tofu and cook until browned.
3. Add Vegetables: Stir in the diced onion, zucchini, and carrot. Sauté until the vegetables are tender, about 5-7 minutes.
4. Incorporate Garlic: Add minced garlic and cook for another minute until fragrant.
5. Add Chunjang: Push the mixture to the side of the pan and add the chunjang. Stir-fry it for 1-2 minutes to enhance its flavor.
6. Combine Ingredients: Mix everything together and add sugar. Pour in the water or chicken broth.
7. Simmer: Bring the mixture to a boil, then reduce the heat and let it simmer for about 5 minutes.
8. Thicken the Sauce: Stir in the cornstarch slurry to thicken the sauce, allowing it to bubble for a few more minutes until it reaches your desired consistency.
9. Serve: In a large bowl, place a serving of noodles and pour the black bean sauce over the top. Drizzle with sesame oil and garnish with chopped green onions.

These straightforward steps will guide you in creating a delicious bowl of Jajangmyeon effortlessly!