Cook lentils in a small saucepan with shallots, thyme, bay leaf, salt, and water. Simmer for 25-30 minutes, then drain and keep warm.
In a separate saucepan, cook potatoes in cold water until easily pierced with a toothpick or knife. Drain and keep warm.
Make the dressing by combining chopped shallot, red wine vinegar, minced garlic, Dijon mustard, salt, pepper, and olive oil. Stir in capers, cornichon, and scallions.
Slice potatoes and place in a serving bowl. Add lentils, dressing, and most of the parsley. Combine and adjust seasoning with salt and pepper. Scatter remaining parsley on top.
Serve alone or with a soft-cooked egg on top, or as a side to a larger roast, chop, or sausages. Reheat as needed.
Keeps in fridge for up to 5 days.
