Bring a medium pot of salted water to a boil and cook the chickpea pasta according to package directions until al dente.
While pasta cooks, season the chicken breast with half of the sea salt and black pepper.
Heat a non-stick skillet over medium-high heat and sear the chicken until cooked through, about 5-6 minutes per side, then remove and slice into strips.
In the same skillet, add the sliced cremini mushrooms, minced garlic, and minced shallot, sautéing until the mushrooms are golden and tender.
Pour in the chicken broth to deglaze the pan, scraping up any browned bits, then stir in the fresh baby spinach until just wilted.
Reduce the heat to low and stir in the Greek yogurt, nutritional yeast, and truffle oil until a smooth, creamy sauce forms.
Toss the cooked pasta and sliced chicken into the sauce, seasoning with the remaining salt and pepper before serving immediately.