Bring a large pot of water (about 4 quarts) with 1.5 tbsp coarse sea salt to boil.
Blanch the broccoli:
Dice off the bottom end of the broccoli stem, about 1.5 inches. Make another cut to separate the florets from the stem. Use the tip of the knife to trim the bottom end of the stem. Slice off and discard rough and thick outer skin. Dice it to 2-inch sections then halve it.
Add the stems to the boiling water and cook until fully tender, about 10 minutes. They will be quite soft. Set them aside to drain. The stems will help produce a silky sauce.
Blanch the broccoli florets for 2 minutes. Keep them crisp and tender. Fish the florets out with a slotted spoon and quickly rinse them in cold water then set aside to drain.
Boil the pasta:
Bring the same pot of water to boil again. Cook the pasta, according to the package instructions. I prefer my noodles al dente. Reserve ½ cup pasta water to thin the pesto sauce.
Make the pesto sauce:
In a high speed blender or food processor, add the broccoli florets and stems with the rest of pesto sauce ingredients from basil to lemon juice. Blend until creamy smooth and bright green. Thin the sauce with the reserved pasta water, 2 tbsp a time until desired consistency. (I use 3 tbsp pasta water). Season with salt and pepper to taste.
Toss the hot pasta with the sauce until they are incorporated well. Season with more salt or pepper, if desired. Sprinkle with paleo parmesan cashew nut cheese, if using. Serve warm or at room temperature.
Swap pine nuts for drained chickpea or sunflower seeds for a nut-free version.To make it low carb or Whole30, lightly saute spiralized zucchini noodles and toss them with the pesto sauce.How to store extra broccoli pesto pasta salad This pasta salad will last in the fridge 3-4 days. Personally I love my noodles warm or at room temperature. To warm up the noodles without reheating, place them in a heat-proof bowl next to your stovetop. As you use the burner to make other dishes, it will warm through the pasta without heating it.Can you freeze broccoli pesto You can freeze broccoli pesto. Add it to an ice cube tray and cover it with a thin layer of olive oil. Once they are solid, pop them into a sealed freezer bag. It’ll keep in the freezer for up to 2-3 months.