This recipe is much like the wonderful salad I had at Manfredi’s house. In Palermo, as I mentioned earlier, the insalate cruda/cotta that you can buy at the markets will vary with the season. In America, we can enjoy that same variety, so do not feel confined by these ingredients: Use other greens such as escarole, mesclun and frisee together with cooked vegetables such as roasted squash, boiled leeks, boiled beets — anything else you have on hand or enjoy.
For the verdura cotta (cooked vegetables): Peel and trim the onions and slice into rounds, about ¾-inch thick. Brush with olive oil and sprinkle salt lightly on both sides. Lay the onions on a baking sheet and roast in a preheated 375° oven for 20 minutes or longer, turning once, until slightly softened and nicely caramelized on the flat sides and edges. Cool, then separate the rounds into thick onion rings.
Meanwhile, drop the potatoes, whole with skin on, into a pot with plenty of water. Bring to a gentle boil and cook just until a sharp knife blade slides through the potatoes — don’t let them get mushy. Extract the potatoes and cut them into wedges, about 1 1/2 inches thick.
Trim the ends of the green beans and, when the potatoes are out of the boiling water, drop the beans in and cook until al dente, 4 minutes or so. Scoop them from the pot with a spider and drop the beans into very icy water, to set the color. Once chilled, drain and dry the beans and cut them in 2-inch lengths.
For the verdura cruda (raw vegetables): Rinse, dry, and core the tomatoes. Slice them in wedges about the same size as the potatoes. Separate, rinse, and spin-dry the lettuce leaves.
Put everything in the bowl except the lettuce: onions, potatoes, beans, olives, capers and tomatoes. Sprinkle over the remaining salt and freshly ground pepper, drizzle over the rest of the olive oil and the red wine vinegar, and tumble the vegetables to coat them with dressing.
Scatter the lettuce on top, tearing the larger leaves in two, then toss the greens with the vegetables gently but continuously for about a minute, to distribute the dressing evenly. Taste and adjust the seasonings, if you like, and toss again.
Serve immediately — always including some of the heavier goodies that drop to the bottom of the bowl and hide under the lettuce.