Make the lemon butter sauce according to the recipe instructions here and keep it aside while you make the pasta.
Wash the asparagus and snap off the woody part of the stems. Slice into 1-inch pieces on a diagonal. Wash Swiss chard and remove the stems but don’t discard. Chop the stems finely and keep them separate. Chop the Swiss chard leaves.
Meanwhile, fill a large pot with water and bring to a boil on high heat. Season the water with a tablespoon of salt.
Add the asparagus and blanch it for 2-3 minutes, until cooked, but still firm. Remove with a slotted spoon and set aside. Next, add the Swiss chard leaves and cook for 3-5 minutes, until soft. Remove with a slotted spoon and set aside.
Now cook the pasta in the same water according to the package instructions.
Meanwhile, slice the red onion and mince the garlic. Heat a large wok or skillet on medium-high heat and add the butter. Add garlic, onion, and the stems of the Swiss chard and sauté until browned.
Add blanched Swiss chard and asparagus to the hot pan to reheat. Follow with cooked pasta and lemon butter sauce. Mix continuously with two spoons until the pasta is evenly coated and warm.
Turn off the heat and serve. Enjoy!
> Get the recipe for Easy Garlic Lemon Butter SauceIf you are making a large amount of pasta, and your pan isn’t large enough, use a separate bowl to mix everything. The pasta can also be warmed or reheated in the oven. Careful not to heat too much, since the butter will separate at high temperatures. However, separation will not affect the flavor.