Combine garlic and chile one a work surface and sprinkle ¼ teaspoon salt on top. Using the side and back of your knife, carefully smash the garlic and chile together to create a paste (see here under "knife-puréeing" for visuals and an explanation of the technique).
Transfer garlic-chile purée to a large mixing bowl and stir in lime juice, fish sauce, and brown sugar. Mix well, taste, and add more sugar if needed.
Add cabbage and toss to coat. Let stand 5 minutes.
Mix in carrot, tomatoes, and apple. Transfer to a serving bowl or plate, top with peanuts and serve.
