In a large bowl, combine the mayonnaise, onion, lemon juice and mustard. Season to taste with salt and pepper.
1 cup homemade mayonnaise, 2 tablespoon grated onion, 2 tablespoon lemon juice, 1 tablespoon dry mustard, sea salt and freshly ground black pepper to taste
Add the shredded cabbage and carrots to the bowl and mix everything together.