Equipment
Ingredients
Walnut Pesto
- 100 g walnuts, raw, shelled
- 3 garlic, peeled
- 30 g fresh basil, washed and dried
- 15 g nutritional yeast
- 15 ml lemon juice, freshly squeezed
- 3 g salt, fine
- 80 ml extra virgin olive oil, high quality
Pasta and Vegetables
- 400 g spaghetti, dried
- 300 g broccoli, cut into bite-sized florets
- 4000 ml water
- 40 g salt
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 757 kcal
- Protein
- 21 g
- Carbohydrates
- 82 g
- Fat
- 38 g
- Fiber
- 7 g
- Sugar
- 5 g
- Sodium
- 325 mg
- Saturated Fat
- 4 g
- Monounsaturated Fat
- 17 g
- Polyunsaturated Fat
- 14 g
- Potassium
- 591 mg
- Calcium
- 99 mg
- Iron
- 3.8 mg
- Magnesium
- 61 mg
- Phosphorus
- 318 mg
- Zinc
- 1.2 mg
- Vitamin A
- 43 mcg
- Vitamin C
- 71 mg
- Vitamin E
- 3.7 mg
- Vitamin K
- 120 mcg
- Vitamin B6
- 0.3 mg
- Thiamin
- 0.15 mg
- Riboflavin
- 0.14 mg
- Niacin
- 0.9 mg
- Folate
- 78 mcg
- Water
- 81 g
Sources: Aggregated Public Data, USDA FoodData Central
Method
Preheat your oven to 160°C/320°F. Spread the walnuts in a single layer on a baking sheet and toast them until golden and fragrant. Allow them to cool entirely to prevent the sauce from becoming greasy.
Bring the water to a rolling boil in a large pot. Add the large quantity of salt to the water, which will properly season the pasta from the inside out.
In a food processor, combine the completely cooled toasted walnuts, peeled garlic cloves, fresh basil, nutritional yeast, lemon juice, and fine salt. Pulse until the mixture is coarsely ground.
With the food processor running on a low setting, slowly stream in the extra virgin olive oil until a thick, cohesive paste forms. Scrape this pesto out into a large mixing bowl large enough to eventually hold all the pasta.
Drop the dried spaghetti into the vigorously boiling water. Stir once to prevent sticking and cook according to package instructions, aiming for a firm, chewy bite.
Exactly 3 minutes before the spaghetti is finished, add the broccoli florets directly into the same boiling pasta water so they cook simultaneously.
Right before removing the pasta from the heat, scoop out and reserve at least 200ml of the highly starchy pasta water. Pour the spaghetti and broccoli into a colander to drain completely.
Transfer the hot, drained spaghetti and broccoli immediately to the large mixing bowl containing the walnut pesto. Add 100ml of the reserved hot pasta water to the bowl.
Vigorously toss the pasta, vegetables, and pesto together using tongs. Gradually add more of the reserved pasta water in small splashes until the oil in the pesto and the starchy water bind together, forming a creamy, glossy emulsion that thickly coats the noodles.
Chef's Notes
- Toasting the walnuts is absolutely non-negotiable for this recipe; it tames their raw, mouth-drying astringency and amplifies their rich, buttery essential oils.
- Cooking the broccoli directly in the same water as the pasta flavors the water slightly, ensures both components finish cooking simultaneously, and saves an extra pot from being washed.
- The starch in the reserved pasta water acts as a mechanical binding agent, magically turning what is otherwise a loose, oily pesto into a lush, creamy, dairy-free emulsion.
- For a milder garlic profile, let your peeled garlic cloves sit in the measured lemon juice for ten minutes before blending. The acid neutralizes the enzyme alliinase, mellowing the harsh bite while retaining deep garlic flavor.
Storage
Refrigerator: 3 days — Store pasta and sauce separately if possible; tossed pasta absorbs moisture and loses its emulsion.
Troubleshooting
The sauce pools at the bottom of the bowl and looks oily rather than creamy
Cause: The emulsion between the olive oil and the pasta water failed to form, usually due to insufficient starch or lack of vigorous agitation
Fix: Add another 20ml of extremely hot pasta water to the bowl and stir or toss violently for 30 to 60 seconds to force the emulsion to coalesce
Prevention: Ensure the pasta water is heavily concentrated with starch by using the minimum required boiling water, and toss the final dish very aggressively
Walnut pesto tastes excessively bitter or astringent
Cause: Walnuts were raw or over-toasted, or the skins were exceptionally tannic
Fix: Balance the final tossed pasta with an extra squeeze of fresh lemon juice and a tiny pinch of salt to mask the bitterness
Prevention: Toast walnuts gently and reliably; for highly refined results, you can rub the toasted walnuts in a kitchen towel to remove some of their bitter papery skins
Cultural Context
Pesto encompasses countless regional variations across Italy far beyond the famous Genovese basil version. Walnut pesto, or pesto di noci, is deeply rooted in the Ligurian and Piedmontese traditions, historically providing vital calories and rich fats during the colder autumn and winter months. Traditional techniques dictate tossing the sauce with starchy pasta water in an unheated bowl rather than heating it in a pan, which preserves the delicate, volatile aromas of the raw garlic, fresh herbs, and extra virgin olive oil.
