Step 1

Combine butter, pasta, broth, 2 cups water, and shallots in a large straight-sided skillet or stockpot; season with salt and pepper. Bring to a boil, then reduce heat to medium-high and cook, stirring frequently, until very al dente, about 5 minutes.

Step 2

Stir in asparagus; cook until crisp-tender, 1 to 2 minutes. Add arugula, Parmesan, and lemon zest; stir to combine. Fold in tuna and lemon juice. Serve immediately, drizzled with oil and sprinkled with more pepper and Parmesan.