Add the potatoes to a large pot of boiling salted water and cook for 30 minutes. Meanwhile, in a small skillet, heat one tablespoon of the olive oil over medium heat. Add the garlic scapes and sauté for about 5-8 minutes, or until the scapes are tender and gently charred. Remove the pan from the heat and set aside. Drain the potatoes and allow them to cool to the point where they are still very warm but you can comfortably handle them. Slice the potatoes into quarters and add to a medium-sized bowl. Pour the stock into the bowl and gently toss.
In a small bowl, whisk the vinegar, lemon juice, garlic, mustard, salt and the remaining oil in order to make an emulsion. Pour the vinaigrette over the potatoes and gently toss. Add the onion, basil, Thai basil, thyme and lentils. Add the cooled garlic scapes and any remaining oil from the pan. Add the freshly cracked black pepper. Gently mix all ingredients to incorporate.