What is the easiest food to grow that doesn’t require fertilizer or pesticides or extensive watering normally for the North West on the Western Side of the Mountains?
Onions?
Check out the book, Growing Vegetables West of the Cascades, by Steve Solomon. I have the 5th ed. but I think there is a 6th by now. The entire book is geared towards gardening without pesticides and with organic fertilizer. For each type of vegetable, its suitability for "dry gardening" is described.