The garden is starting to come in again — fresh chives on my morning egg for the past couple of weeks, the mint is coming back so my morning pot of tea tastes fresh and green again, and as always, onions are poking up from all sorts of odd places among the perennials. I’ve begun planting, the tomato, pepper, eggplant and cucumber seedlings are in the cold frame. And it’s spring, so I’m craving greens — spinach or asparagus, for example. But at the supermarket I look at those crinkly packages of baby spinach, or mixed greens and I just…