2 tablespoons olive oil.
1 bunch shallots, white and green, thinly sliced and separated.
Kosher salt and freshly ground black pepper.
1 2 teaspoons dried oregano.
Pinch the red pepper flakes.
1 garlic clove, minced.
Zest and juice of 1 lemon.
12 ounces of pasta (or thick pasta).
1 3 cups grated Parmesan cheese (about 1 ounce).
1 3 cups whole ricotta cheese.
Heat the olive oil in a large thick-bottomed saucepan over medium-high heat (an oval Dutch oven or round saucepan works well here, but any large pot will do). Add green onions, 1 teaspoon salt, and a few grains of ground black pepper and cook for 3 to 4 minutes, stirring occasionally, until tender and begin to caramelize. Add the oregano, crushed red pepper flakes, and garlic and cook, stirring until the garlic is tender and fragrant, about 1 minute.
Add lemon juice, 5 1 2 cups of water, 1 teaspoon salt, and a few grains of black pepper to the pan and scrape off any brown pieces that may have formed at the bottom. Place the pasta in the pan and spread it out as much as you can. Bring the water to a boil and cook, stirring often to make sure the pasta doesn't stick to the bottom of the pan until the pasta is dente, the mixture looks creamy and starchy, and almost all of the water has evaporated, 10 to 12 minutes.
Remove from heat and stir in Parmesan, ricotta and lemon zest until cheese is melted and the sauce is very creamy, about 1 minute. Divide the pasta into 4 bowls, each garnished with green shallots and a few pieces of black pepper.