In general, sauteing or stir-frying are great method of cooking food, as long as the cooking oil is well chosen (avocado oil, olive oil) and not overdome. Otherwise, raw lettuce and cucumbers best maintain vitamin K, the former also maintaining vitamin A and the latter potassium. Raw vegetables are also very water dense, as spinach , bell peppers, tomatoes, courgette, celery, lettuce and cucumbers are all 91-95% water, providing excellent hydration. Mix and matchLastly, some foods act as a lock-and-key system, where one ingredient helps absorb micronutrients of the other. Myrosinase in mustard seeds converts glucosinolates in broccoli into sulforaphane, a plant compound known to be antioxidant, anti-inflamatory and antimicrobial, and the fiber in oatmeal helps absorb antioxidants in berries.