Gather a large skillet and heat the olive oil over medium heat until it shimmers softly, releasing a grassy aroma. Add the diced onion and sauté for about 5 minutes, stirring frequently, until translucent and just starting to turn golden.
Add the minced garlic to the skillet and cook for 30 seconds until fragrant, being careful not to let it burn—look for a golden hue and a warm aroma filling the kitchen.
Stir in the chopped tomatoes and cook for about 10 minutes, breaking them down with the back of your spoon as they soften and release their juices. The mixture should become glossy and slightly thickened, filling the air with a sweet, tangy scent.
Meanwhile, drain the soaked cashews and transfer them to a blender. Add a splash of water, a squeeze of lemon if you like, and a pinch of salt. Blend until very smooth and silky—this should take about 1 minute, and the sauce should feel oozy and luxurious.
Pour the cashew cream into the simmering tomato sauce, stirring well to combine. Let it simmer gently for another 5 minutes, allowing the flavors to meld and the sauce to turn velvety. You’ll notice the aroma deepening, with hints of garlic and fresh tomato.
Meanwhile, bring a pot of salted water to a boil. Add your pasta and cook until al dente, about 8-10 minutes. Before draining, save about half a cup of pasta water—you’ll use it to loosen the sauce later if needed.
Drain the pasta and add it directly into the skillet with the sauce. Toss gently to coat each strand or piece evenly, adding a splash of reserved pasta water if the sauce feels too thick or sticky. Cook together for 1-2 minutes to allow the flavors to meld beautifully.
Remove from heat and stir in the chopped fresh basil for a burst of bright, peppery aroma. Taste the sauce and adjust seasoning with a pinch of salt or a squeeze of lemon for extra zing.
Serve the pasta hot, garnished with additional basil if desired. The sauce should be glossy, velvety, and cling to the pasta, with a vibrant tomato and basil aroma that invites you to dig in.
