Once you begin cooking, this pasta comes together very quickly! Start by getting all of the chopping, measuring & other prep steps out of the way so cooking is a smooth process: dice the shallot, grate/dice the garlic, trim & chop the asparagus, dice the chicken, measure the cheeses, etc. Place everything within an arm’s reach from the stovetop.
Bring a large pot of water to a boil. Once boiling, generously salt the water. Add the pasta and cook to al dente according to package directions. About 90 seconds before al dente is reached, add the chopped asparagus to the pot to blanch with the pasta as the pasta finishes cooking. Reserve 1 cup of the starchy pasta water. Drain the pasta and set aside.
Meanwhile, cook the aromatics & chicken. Add the olive oil to a 12-inch skillet over medium heat. Once hot & shimmering, add in the shallot. Cook 1-2 minutes, stirring occasionally, until softened & aromatic. Add in the chicken, seasoning with 1 tsp. S&P as desired. Cook 5-6 minutes, stirring occasionally, just until chicken is cooked through. Add in the garlic & stir to combine.
Increase heat to medium-high. Deglaze the pan with 1/4 cup of the reserved pasta water, using a wooden spoon or spatula to scrape up any browned bits that may have formed at the bottom of the pan. Add the mascarpone & parmesan. Simmer 2-3 minutes, stirring occasionally, until mascarpone is melted & the sauce is thickened slightly. Stir in the white balsamic vinegar.
Add pasta, blanched asparagus, sweet peas, & spring greens to the skillet with the chicken & mascarpone sauce. Toss to combine. Cook 1-2 minutes more, bringing everything together & allowing the greens to wilt slightly. If needed, adjust the sauce – add in more mascarpone to make it creamier, more pasta water to loosen it up, or more parmesan to thicken. Taste & season with S&P.