For the potatoes:
Preheat the oven to 500, and bring a large pot of water to a boil. Peel and slice the potatoes into 1 inch slices. When the water is boiling, add in the potatoes and boil for 10 minutes, then drain. Line a large baking sheet with foil, and rub with olive oil. Spread out the potato slices onto the baking sheet and spray the top with olive oil. Bake for 25 minutes, turning halfway through.
For the salad:
Dice the parsley, red onion, and Escarole. Add the diced veggies into a large bowl. Rinse and drain the beans, and toss with the vegetables.
For the dressing:
Mince the garlic and roughly chop the capers. In a small dish, whisk together the mayonnaise and juice from 1/2 the lemon, and then add in the garlic and capers.