Kale & Spinach Pesto Pasta
Everything goes into the blender. Kale, spinach, garlic, Parmesan, mixed nuts, olive oil, lemon juice — one press of the button and you have a pesto thick enough to coat hot fettuccine. 15 minutes, one pan for the pasta, one blender for everything else.
That blender step changes the nutrition. A human study found that liquifying spinach instead of eating it whole nearly doubled the beta-carotene the body could absorb — from 5.1% to 9.5%. Blending cracks open plant cells that normally trap carotenoids inside. The olive oil, nuts, and Parmesan blended in with the greens give the freed nutrients a fat to dissolve into. The pesto is not just a sauce.
Ingredients
- fettuccine 84 g
- kale (frozen) 112 g
- spinach 112 g
- garlic 1 clove
- Parmesan 28 g
- mixed nuts (unsalted) 28 g
- olive oil 15 ml
- lemon juice 5 ml
Method
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Cook fettuccine in salted boiling water until al dente. Drain and reserve.
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Thaw kale fully and squeeze out any excess moisture.
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In a blender or food processor, combine kale, spinach, garlic, Parmesan, mixed nuts, olive oil, and lemon juice. Blend until smooth.
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Toss hot pasta with pesto until evenly coated.
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Serve immediately.
Blend the pesto until genuinely smooth, not chunky. The finer you blend the greens, the more plant cell walls break apart and the more beta-carotene your body can absorb. A study on liquefied vs whole-leaf spinach found the difference was nearly double. The blender is doing nutritional work your teeth cannot.
The body absorbs beta-carotene from spinach at just 5.1% when the leaves are eaten whole. Most of the pigment stays locked inside intact chloroplasts behind rigid cell walls. Liquifying the same spinach pushed absorption to 9.5%. Adding dietary fat helps the freed carotenoids form absorbable structures in the gut. This recipe does both in one step.
Castenmiller et al., J Nutr 1999 · DOIWhy This Works
Behind this recipe
Is frozen kale as nutritious as fresh kale?
Most minerals and fiber survive commercial freezing. The main trade-off is myrosinase, the enzyme cruciferous vegetables use to produce sulforaphane. Commercial blanching before freezing destroys it. That does not make frozen kale less valuable. It means one specific pathway is lost while the vitamins, minerals, fiber, and carotenoids stay intact.
Read the full evidence reviewDoes the oxalate in this much spinach block the iron?
A controlled study tested exactly this. Women ate spinach with and without added oxalic acid, and the researchers measured iron absorption using stable isotopes. The result: oxalic acid had no measurable effect on non-heme iron absorption (P = 0.86). The garlic and lemon juice in this pesto both independently enhance iron absorption, through sulfur compounds and vitamin C respectively.
Read the full evidence reviewWhy does the garlic go in raw instead of being sautéed first?
Garlic contains an enzyme called alliinase that converts alliin into allicin when the clove is crushed. Cooking destroys alliinase. In this recipe, the garlic is crushed by the blender and served immediately in the pesto, so the allicin pathway stays intact. Most pasta recipes sauté garlic first, which deactivates the enzyme before it finishes its work.
Read the full evidence reviewCan I use a different pasta shape?
Any long pasta with a rough surface works well. Fettuccine, tagliatelle, and linguine all catch thick pesto. Smooth, thin shapes like angel hair let the pesto slide off. Short pastas like penne work but change the texture balance.
