How to make arugula pesto. For full instructions and notes, see our Arugula Pesto recipe, but in a nutshell: Add 4 cups fresh arugula, 1/2 cup walnuts, 1/2 cup parmesan cheese, 2 cloves garlic, and 2 Tablespoons lemon juice to a food processor with a generous pinch of kosher salt. Pulse a few times to combine, then stream in 1/2 cup good olive oil a few Tablespoons at a time while the food processor runs until you have a smooth pesto (you may not need all the olive oil).

Shred your own cheese for best results. Store-bought shredded cheese is often coated with preservatives that prevent the cheese from melting smoothly. Buy a block of white cheddar and shred it yourself for best results! If your cheese sauce does separate, zap it a few times with an immersion blender to smooth it back out.

Additions and Substitutions. Use basil pesto or cilantro pesto in place of arugula pesto if you like. Swap some or all of the white cheddar cheese for goat cheese, havarti, or fontina. Use our Magic Cauliflower Cream in place of some or all of the milk (if you replace all of the milk with cauli cream à la our cauliflower mac and cheese, you can also omit the flour and butter). Swap up to 1/2 cup of the milk for white wine or chicken stock.