Squeeze the lemon into the bottom of a large serving bowl. Add olive oil and whisk until emulsified. Taste and add more lemon or olive oil to taste. Add salt and pepper.

Gently tear spinach and add to the bowl. Top with toasted pine nuts and grated parmesan cheese. Toss and serve.

*The general rule of thumb for making a vinaigrette is a ratio of 3:1. 3 parts oil to 1 part vinegar, in this case lemon juice. I like this dressing lemony, so I use a more equal ratio.