Each food item has its own unique properties. There may be benefits and some defects. We have to decide on the priority, preference and optimum use based on various parameters.
Garlic is a very unique one having a lot of protective and medicinal properties. Onion also has some very good contributing uses apart from its tasty use and combinative property to go with any food. Hence to avoid them and go for substitute many not be an easy alternative.
However it is the offensive odour in Garlic and the 'tearcausing' property of Onion that creates some problem for its users. They are both analysed to have Sulphur compounds in them that cause these characteristics.
Hence the object here is to use alternatives that will have Sulphur in them but not as offensive causing as these two.
The vegetables and food items that have sulphur in good quantity are:
1. Cruciferous Vegetables: Cauiflower, cabbage, broccoli, turnips etc.
2.Protein foods: nuts and legumes, fish, poultry(including eggs) etc.
3. Fruits: Avocado, Kiwi, Banana, Pineapple, Grapefruit, strawberries, melons etc.
4. Others: Lettuce, Spinach, Soya bean, sweet corn etc.
However the odour of Garlic and Onion can be reduced with some kitchen tricks. One is copious washing and cutting under water itself in the vessel. Adding ginger, bread crumbs , adding some extra turmeric etc.