For a protein boost, consider adding cooked chicken or shrimp to the fettuccine. You can also incorporate some fresh spinach or peas for added color and nutrition, which could appeal to picky eaters. If you prefer a bit of tang, try adding a squeeze of fresh lemon juice or a pinch of nutmeg to the sauce. For those who enjoy a bit of heat, a dash of red pepper flakes can spice things up nicely.