My 11 month old has recently become a very fussy eater so I will be moving him from steamed to sautéed vegetables. Is it better to cool with butter or olive oil?

I personally would choose butter over olive oil, simply because it would taste a lot nicer. Of course I wouldn't use a lot for my child, but a small amount for taste would do. Olive oils are great, but my daughter much prefers it with butter. And as I searched online to see if butter or olive oil is a healthier choice, it turns out that butter is in fact a better choice than olive oil. Butter has a higher density of nutrients like K2 and is mostly made up of heart healthy saturated fat while being low in polyunsaturated fat. Olive oil is high in polyunsaturated fatd. Saturated fats are extremely healthy, while polyunsaturated fats are the undesirable fats we shoud avoid. Here's an article that is more in-depth about the benefits of Butter. http://www.ancestral-nutrition.com/which-is-healthier-butter-or-olive-oil-2/

Just to add on that you should use unsalted butter since your baby is below 1 year of age. As for me I think I would alternate my uses. So sometimes butter and sometimes olive oil. Don't have to be too strict about one. You could also consider using extra virgin coconut oil. Coconut oil is rich in lauric acid which boosts baby’s immune system and helps in digestion. You can also use it for many other uses as well! http://sg.theasianparent.com/virgin-coconut-oil-benefits-for-babies/

I would prefer butter as butter is mostly made up of heart-healthy saturated fat and is low in polyunsaturated fat, while olive oil is mostly monounsaturated fat and has a higher PUFA content. Saturated fats are extremely healthy, while polyunsaturated fats are the undesirable fats we should avoid

Feel free to add butter to their diet. Butter is a dairy product that has a very high fat content. Because of this, you should limit your child's intake of butter. You can start using olive oil after they grow up.

Here's an pdf that is more in-depth about the baby food. https://www.cyh.com/library/foods_for_babies_and_toddlers_A5_2016.pdf

thanks