Cover the baby potatoes with water in a large pot, bring to a boil and reduce to a rolling simmer until potatoes are cooked through. (anywhere from 10 to 20 minutes, depending on the size of the potatoes).
While the bay potatoes are boiling, whisk together the olive oil, lemon juice and zest, and big pinch of salt and pepper, and the shallots.
When the potatoes are done, drain them, and using a cloth to protect your fingers, cut them into bite-size chunks (if your potatoes are very small, this might be in half. If they are larger, you might want to quarter them).
Return them to the pot, add the butter olive oil mixture, and toss around. Add all the greens, and mix again until everything is coated. Add more olive oil if needed, and add more salt and pepper to taste (potatoes tend to need a lot of salt, so don’t be afraid to keep adding more until it tastes right).
Serve while still warm, or it can sit for a little while, and it tastes just as fantastic at room temperature.