Heat the oil in a large pot over medium heat. Add in the onion and garlic and cook until fragrant and transparent.
Add in vegetable scraps, followed by the water, making sure the water covers all the veggies.
Add in the bay leaves.
Bring to a boil and then reduce to low. Cover and let simmer for at least 1 hour.
Scoop out veggie chunks with a large slotted spoon or strain broth through a colander. Then strain again through a fine-mesh sieve.
Pour into a clean jar and let cool.
Store in the refrigerator for up to 1 week.
I usually don't add any salt to my vegetable broth since it often gets added to a dish where I'm adding spices and salt anyway. If you wish to add salt to your broth, add it once it has cooled for a few minutes (just before jarring).
*The longer you let the vegetable scraps simmer, the more the water will evaporate, and the stronger it will taste. If it turns out stronger than you desire, you can always mix in some fresh water to dilute it!*Try to buy organic produce whenever possible to reduce exposure to harmful toxins and xenoestrogens.