I'm surprised nobody mentioned dandelion greens. I remember when i was a kid my mother, grandmother, italian neighbor and all her female friends would go with their aprons and a little knife digging up dandelion leaves, the young tender ones, We always ate them as a salad.
You can talk all your salad greens including arugula, and toss them, i'll take dandelion greens any day. They need salt, pepper, oil and vinegar, and you should eat the salad with lots of crusty bread (dunking in the oil mixture at the bottom of the dish when you're done. They're slightly bitter, and very tasty.
Some people cook them but i much prefer them raw.
And want an amazing sandwich? some good no knead artisan bread with some of this salad with its oil and vinegar salt and pepper on it, and some slices of parmigiano.
I never liked it at the time, but chicory is also great, but a little more bitter than the dandelion, but are good boiled and then eitehr eaten with olive oil and lemon or you heat a frying pan with some garlic in it and olive oil and when the garlic is partly cooked, add the drained greens and toss while cooking. wonderful.
These bitter greens are a perfect foil for a heavy meat course - their bittereness seems to help your digestion,
