To a blender or food processor, add the olive oil, arugula, peas, zest, lemon juice, ricotta, parmesan, crushed red pepper and a few pinches of salt. Pulse until the pesto is smooth, scraping down the sides as needed. Give it a taste and adjust the salt to taste. Set aside.: The aroma at this stage is herbaceous and bright, with the citrus oils from the lemon zest lifting the arugula and basil . As the blades chop, you will hear a steady, hummed sound and see the mixture transform from leafy pieces to a glossy, cohesive sauce. The creamy ricotta cheese softens the texture, turning the pesto toward silkiness rather than grainy paste, and the Parmesan-Reggiano adds savory depth. Pause to scrape the sides often so no pockets of unblended leaves remain, and taste for salt and brightness. If it tastes flat, add a touch more lemon juice or salt incrementally. A common mistake here is overprocessing until the pesto becomes too watery or warm, which dulls the color and vibrancy, so pulse in short bursts and keep the motor cool by pausing occasionally.
Bring a medium pot of salted water to a boil. Cook the angel hair pasta per the package’s instructions (mine said about 6 minutes). Reserve about a 1/2 cup of pasta water (you can eyeball this measurement). Immediately return the pasta to the pot. Add the pesto and toss until evenly coated. If needed, add a splash or two of pasta water.: The pot will sing as it reaches a rolling boil, and salted water is critical because it seasons the angel hair pasta from the inside out. Watch the pasta closely, since angel hair pasta cooks very quickly and goes from al dente to mush in moments. When you lift a strand, it should show a slight firm center, and the surface will glisten with starch. Reserving that pale, starchy pasta water is a chef trick, since those suspended starches help the pesto bind to the noodles, giving a silky, clinging sauce. Toss vigorously to marry the pesto and pasta, adding tiny amounts of water to loosen or thicken the consistency. Avoid rinsing the pasta, which washes away the starch that helps the sauce adhere.
Meanwhile, in a small skillet, set over medium-high heat, add the ghee or butter. When hot, add the scallops and sprinkle them with a few pinches of salt. Cook for 3 to 4 at a time, as to not crowd the pan. Cook on the first side for about 30 seconds to 40 seconds; flip and cook on the opposite side for about 30 seconds. Repeat until you’ve worked your way through all of the scallops.: As the ghee or butter melts and heats, watch for a foaming then a settling where the milk solids begin to brown and emit a toasted, nutty scent that signals brown butter. Carefully add the scallops , and you should hear a bright, high sizzle as they hit the pan, indicating proper heat for searing. They will develop a golden to deep amber crust in those short bursts, and the contrast between the toasty exterior and the tender, opaque center is key. Work in small batches so the pan temperature does not drop, otherwise the scallops steam and fail to brown. A typical error is overcrowding, which leads to pale, rubbery results; give them space and keep a close eye on the color and smell of the butter to avoid burning it.
Divide the pasta and scallops amongst bowls. Garnish with a few sprigs of basil and Parmesan.: At plating, the steam will lift aromatics from the pesto, making the room smell herbaceous and tangy. Arrange the sauced angel hair pasta in shallow bowls, nestling the warm, browned scallops on top so each bite gets a balance of sauce and seared seafood. A final scatter of grated Parmesan-Reggiano adds a salty finish, and a few torn basil leaves refresh the palate with bright green notes. Be mindful not to pile the scallops on top of one another, which can trap steam and soften their crust. If the pesto cooled too much while you seared, toss it briefly over low heat with a splash of reserved pasta water to loosen it before plating.
