Pour 2 tablespoons of the olive oil to a large pan, and set heat to medium. Add diced pancetta, and cook, stirring occasionally, until pancetta is browned, and most of the fat has rendered out, 7 to 10 minutes. Turn off heat.

Remove some pancetta and reserve to garnish the top if desired. Pour out some of the excess pancetta fat from the pan if desired, but leaving at least 2 or 3 tablespoons.

Add green onions, and turn heat to medium-low. Sauté green onions for a few minutes to soften slightly, then turn off heat and reserve until pasta is cooked.

While pancetta is cooking, bring a pot of well-salted water to a boil. Add rigatoni, and set a timer for 2 minutes less than recommended cooking time for the pasta, or about 7 minutes for mezzi rigatoni. Stir occasionally.

Meanwhile, combine parsley, basil, mint, garlic, lemon juice, and water in the jar of a blender or a cup; blend in the blender or with an immersion blender until smooth. Set aside.

When timer rings, stir in asparagus and peas and continue cooking for 2 minutes, or until pasta is done to your liking. Use a strainer to transfer pasta and vegetables into the pan with pancetta.

Turn heat to medium-low and pour in herb mixture. Stir until combined. Season with salt, and drizzle in about 1 tablespoon olive oil. Add about ¼ cup pasta water, and stir over medium-low heat until everything is hot.

Turn off heat, and stir in cheese. Taste for seasoning, and serve immediately. Garnish with more cheese, reserved pancetta, and more sliced green onions.