This creamy, velvety carbonara is deceptively healthy. It's loaded with spring vegetables, caramelized to a delicate sweetness, studded with just the right amount of salty pancetta, and sprinkled with Parmesan cheese to finish the dish (and there's not a drop of heavy cream in sight). —Meg Salvia
Dice the pancetta into small cubes, about 1/4 to 1/2 inch thick. Prep the vegetables before starting: roughly chop the garlic and set aside. Thoroughly wash the leeks and spring garlic bulbs (rinse between the layers to remove all residual dirt). Chop the root and the rough leaves off the ends of the plant; you should have between 6 and 8 inches of leek and garlic stalks to use. Halve the stalks lengthwise. Cut each stalk into 4-inch pieces. Continue to cut the stalks lengthwise to achieve slivers (I found quartering each half worked well). Slice the red onion.
Over medium heat, cook the pancetta until most of the fat has rendered off (it won’t be much), and it starts to brown and crisp, but not burn. Transfer the cooked pancetta to a plate and drizzle the olive oil to the pan. Add the chopped garlic cloves and cook 2 minutes. Add the remaining vegetables and cook until wilted and starting to color, about 10 more minutes.
Meanwhile, bring a large pot of salted water to a boil. Cook the spaghetti according to package directions. Before draining, reserve at least 1 cup of the pasta water. Drain and return to the pot.
Combine the eggs, egg yolks, Parmesan, and 1/2 cup of the pasta water. Whisk quickly to ensure the egg doesn’t start to cook and curdle in the warm water. Combine the vegetables, pancetta, and pasta in the large pot. Pour the carbonara sauce over the pasta and stir – very quickly – to coat evenly. Working fast here is the key to not having scrambled eggs develop on top of your spaghetti. Season with salt and pepper and top with grated Parmesan cheese. Serve immediately.