Is it bad to cut onions and other vegetables on the same cutting board? Does the type of cutting board matter? For example, do wooden cutting boards that are regularly used to cut onions (or other potent veggies, garlic, etc.) start to smell permanently like onions?
No it isn't bad.
It's all a matter of flavor. I don't really mind getting some onion juices into my next dish, unless I'm making something sweet like fruit salad - in this case I would rinse the board before moving on.
My advice to you about boards is: Get yourself a proper wooden or bamboo board or butcher's block, treat it with care (clean it an soak it with mineral food grade oil every now or than...) and that's all you'll even need.
I've been using my favorite board for over 10 years now. And it doesn't smell of onions.
Assuming that you'll soon be cooking the vegetables in the same pan as the onions/garlic, you have little to worry about in terms of 'contaminating' the former with the latter.
Softer boards will accumulate scores and grooves from knives which will trap oils and juices from onions and garlic which may eventually start to make them smell. However, it's a good idea to replace your cutting boards every few months anyway to guard against bacteria build up, so it shouldn't be too much of an issue.
Is it bad to cut onions and other vegetables on the same cutting board?
Cutting board flavor transfer concerns are a factor of:
- Is it really important to the recipe at hand? Example, if cooking a gumbo, cutting board protocol is simply not needed. Some recipes might need special handling, but none come to mid.
- What is the cutting board surface (maple, bamboo, plastic, glass etc.)
- How you clean the cutting board: frequency of cleaning and does the method of cleaning match the board material
I cooked in restaurants for 10 years, and at home for 40 years: I've never had a problem with undesired flavor transfer of onions (or garlic, or shallots, or powerful seafood etc.).
Whatever your cutting board is made of... come back here and research how to clean it.