Heat a drizzle of olive oil in a skillet. Add mushrooms and sauté until browned. Set aside.
Using a mandolin or sharp chef’s knife, thinly slice turnips and reserve.
Whisk together 4 tablespoons olive oil, vinegar, a good squeeze of lemon and minced ramps. Season with salt and pepper, to taste.
Squeeze juice from 1 lemon into a large bowl of ice water. Working with one artichoke at a time, cut off and discard the stems. Pull off the dark outer leaves until you reach the tender yellow ones. With a serrated knife, cut an inch off the top of each artichoke; using a mandolin or sharp chef’s knife, slice chokes vertically and very thinly. As you work, immediately add the artichoke slices to the lemon water. This will prevent them from browning. When completely sliced, drain, blot dry, and transfer to a large bowl. Add turnips, mushrooms and dressing. Toss to coat and serve.