Vinegar Coleslaw

Name: Vinegar Coleslaw
Ingredients: 2 c. shredded purple cabbage (about ¼ medium head); 5 c. shredded green cabbage (about ⅔ medium head); 2 c. shredded carrots (about 4 medium); 1.5 tsp. kosher salt; 2 tbsp. extra-virgin olive oil; 2 tbsp. apple cider vinegar; 2 tbsp. Dijon mustard; 2 tbsp. maple syrup; 0.75 tsp. freshly ground black pepper; 1 clove garlic, grated or minced; 1 scallion, thinly sliced; 0.5 tsp. celery seed; 1 tbsp. toasted sesame seeds (optional); 1 tbsp. poppy seeds (optional)