Mint, especially peppermint is good for upset stomachs; as a tea or 2 drops peppermint oil to a large glass of water to sip., also good to get rid of gas. Also helps with headaches when taken as a tea.
By onion grass, do you mean chives? Chives can be used in salads, and as replacement for onions for those who are bothered by them. Garlic chives does the same. I grow both. I'm growing mint, too. And blueberries, on my. It can be used for baking and just plain eating. To me, it has some of the same affects as chocolate, and is full of antioxidents. You have a nice garden there. Blessed Be...