Bring a pot full of water to the boil over high heat. Add the salt and the pasta. Cook the pasta according to the instructions on the package. Reserve 150-200 ml (about 1 cup) of the pasta water before straining.: The moment you start hearing the water roar and seeing big rolling bubbles, you know it is hot enough to add salt and farfalle . The steam should feel lively and slightly sharp on your face, and the kettle like hiss signals readiness. Why this matters, because pasta added too early will cook unevenly and release excess starch. A common mistake is under salting the water so the pasta tastes bland; always season until the water tastes slightly like the sea. If you see violent foaming, reduce heat briefly to avoid messy boil overs.
Put the broccoli, anchovies, parmesan, olive oil and garlic in a food processor. Season with salt and pepper, mash well and set aside.: When the farfalle hits the water you will hear a lively bubbling change and the pasta should start moving freely. Stir immediately so the shapes do not cling together, and keep an eye on the clock provided on the package. Cooking to an al dente texture means a tooth encountering gentle resistance, which gives better mouthfeel and prevents mushy results when you finish in the pan. A typical slip up is failing to stir regularly, which can cause clumping or uneven cooking, so give it a good stir every minute or so.
Place a large pan over medium heat. Once hot, add the butter, a little olive oil and pasta broccoli and sauté a little.: As the farfalle cooks you will notice the aroma change from raw starch to a toasty, wheaty scent, and the shapes will turn uniformly opaque. Taste a piece a minute or two before the suggested time to find the perfect bite. Overcooking is the usual error here; drain a touch early if you plan to finish cooking in the sauce, because the pasta will continue to soften when combined with hot ingredients.
Remove the pan from the heat, add the broccoli pesto, water from the boiling pasta and the farfalle. Stir well and serve.: That warm, cloudy liquid will shimmer and smell faintly of cooked wheat, and it is key to making the pesto silky. Measure roughly but remember you can always add more to loosen the sauce. A typical mistake is rinsing pasta after draining, which removes the starch needed for emulsifying the sauce, so never rinse if you want a glossy finish.
Put the broccoli anchovies parmesan olive oil and garlic in a food processor: When you load the ingredients into the processor you will see the vibrant green of the steamed broccoli and the glint of olive oil , and the aroma of garlic will lift as you pulse. Pulse gently to combine, stopping to scrape down the sides so everything is evenly integrated. The texture should become a coarse paste that still shows flecks of broccoli , not a watery slurry. Overblending can heat the mix and dull the color, so pulse in short bursts and add a splash of reserved pasta water if needed to reach the right consistency.
Season with salt and pepper mash well and set aside: After pulsing, press a small taste of the pesto onto the roof of your mouth to check seasoning; the anchovies bring saltiness, so adjust cautiously. The aroma should be herbaceous with umami depth, and the texture should cling to a spoon. Letting it rest allows flavors to marry, but avoid leaving it unrefrigerated for long periods because fresh garlic can become harsh if exposed to heat. If you find it too sharp, a touch more olive oil or a sprinkle of parmesan will mellow it.
Place a large pan over medium heat: You want the pan to feel warm to the touch over medium heat and to emit a subtle, dry hiss when a drop of water flicks into it. This controlled heat helps gently sauté without burning, which preserves the sweet edges of the broccoli . If your pan gets too hot it will smoke and the flavors will scorch, so lower the temperature if you notice a sharp scent.
Once hot add the butter a little olive oil and pasta broccoli and sauté a little: As the butter melts you will see it foam and then settle, offering a nutty scent, while the tiny sizzle from the broccoli hitting the pan signals caramelization. Sauté just until the florets develop a few golden flecks and the aroma becomes toasty, which deepens flavor. Avoid crowding the pan, which causes steaming rather than sautéing; work in batches if needed to get those desirable seared bits.
Remove the pan from the heat: Lifting the pan off direct heat prevents the residual temperature from overcooking delicate ingredients and keeps the next emulsification step gentle. The pan will still be warm enough to help marry the sauce without risking the pesto turning oily or breaking. A common trap is leaving it on heat, which can cook the blended pesto too much and make it lose brightness, so take it off promptly.
Add the broccoli pesto water from the boiling pasta and the farfalle: When you fold in the reserved pasta water the sauce will begin to shine and cling, and the steam will carry the savory perfume of parmesan and anchovies . Toss the farfalle so the sauce slips into every curve, watching the texture change to a creamy coating. If the sauce seems slack, add another spoonful of the warm pasta water; if it is too loose, let it sit a moment so the starch can bind. Do not drown the pasta with water, as that dilutes flavor.
Stir well and serve: The finished dish should glisten lightly, and you should notice a balanced interplay of savory, creamy, and green notes. Serve immediately while warm, and consider finishing with an extra grate of parmesan or a crack of pepper if you like. Common mistakes here include letting the pasta sit too long which causes the sauce to clump or dry; plate promptly for best texture and flavor.