-
Rinse Swiss chard with cold water. Pull the leaves from the stems. Slice the stems into 1/4-inch pieces. Cut the leaves to 1-inch thick strips.
-
Drain, pat dry, or use a salad spinner to remove excess water from leaves.
-
Cook the pasta according to package instructions. Reserve 1/2 cup of the pasta water. Drain pasta and return it to the pot.
-
Add corn to the pasta.
-
While the pasta is cooking, heat the oil in a large skillet over medium heat.
-
Add the onion and chard stems and cook until tender, about 5 to 6 minutes.
-
Add the garlic and cook, stirring, until fragrant, about 1 to 2 minutes.
-
Add the chard leaves, salt, and pepper to the skillet. Cook, tossing with tongs or turning with a spoon, until leaves are just tender, about 3 minutes.
-
Toss the pasta and corn with 1/4 cup of the reserved pasta water. Fold or toss in the chard mixture, lemon juice, and 1/4 cup parmesan.
-
If the pasta seems dry, add more pasta water, 1 tablespoon at a time.
-
Transfer to a serving bowl or platter. Sprinkle with additonal parmesan if desired.