Prep the chicken and aromatics: pat the chicken breasts dry with paper towels (dry surface = better sear). Season both sides generously with salt and 1/2 tsp black pepper. Peel and finely dice the onion and mince the garlic. Cutting the chicken to an even thickness (slice in half horizontally if thick) ensures the pieces cook evenly and finish at the same time.

Bring a large pot of salted water to a rolling boil and start the pasta: add 1 tbsp salt per 4–6 L of water, then drop in the chickpea pasta and cook to 1–2 minutes before the package 'al dente' time. You’ll finish cooking the pasta in the sauce, so slightly undercooking preserves texture and prevents mushy noodles. Reserve 1 cup (240 ml) of pasta cooking water before draining.

Sear the chicken for a golden crust: while the water comes to a boil, heat a large wide skillet over medium-high heat and add the olive oil. When the oil shimmers, add the chicken and sear without moving for 3–4 minutes until a deep golden crust forms—this Maillard reaction builds flavor. Flip and cook the other side 3–4 minutes until the chicken is mostly cooked through (internal ~155°F/68°C). Transfer to a cutting board to rest 5 minutes; resting lets juices redistribute so the chicken stays moist.

Thinly slice or dice the rested chicken into bite-sized pieces: cutting after resting keeps the meat from losing juice during slicing. Set aside.

Build the flavor base: reduce the skillet heat to medium and add the butter. Once it foams, add the diced onion and a pinch of salt. Sweat the onion 4–5 minutes until soft and translucent—sweating (rather than browning) releases sweetness that underpins the sauce without creating bitter caramelization. Add the garlic and red pepper flakes and cook 30–45 seconds until fragrant; this short time prevents garlic from turning bitter.

Deglaze and simmer: pour in the chicken stock and scrape up any browned bits from the pan (those bits are concentrated flavor). Let the stock reduce by about one-third over 3–4 minutes—reducing concentrates flavor and gives the sauce body so you need less cream.

Add cream and gentle heat: lower the heat to medium-low and stir in the heavy cream. Heat until the mixture is warm and slightly thickened—do not boil hard, as high heat can separate cream. Warming the cream slowly keeps a smooth, glossy sauce.

Temper the Greek yogurt for creaminess and protein: put 2–3 tablespoons of the warm cream-stock mixture into a small bowl and whisk in the Greek yogurt to loosen it (tempering prevents curdling). Then stir the yogurt mixture back into the skillet until fully incorporated. This technique keeps the sauce silky while adding protein and tang.

Finish the sauce with Parmesan and pasta water: stir in the grated Parmesan and 1/4–1/2 cup reserved pasta water as needed to reach a glossy coating consistency. The starch in the pasta water acts as an emulsifier, helping fat and liquid bind to the noodles for a clinging sauce.

Combine chicken and pasta: return the sliced chicken to the skillet and add the drained pasta. Toss gently over low heat for 1–2 minutes to marry flavors and finish pasta cooking—this step lets the pasta absorb sauce while the chicken warms through without overcooking. Taste and adjust seasoning with salt and pepper.

Rest briefly and serve: remove from heat, sprinkle chopped parsley and an extra shave of Parmesan if desired. Let the dish sit 1–2 minutes so the sauce settles—this yields a slightly thicker coating on the pasta when plated.

Plate and enjoy: divide into 4 warmed bowls so the sauce stays glossy. Serve immediately.