Bring a pot of salted water to a boil and cook the chickpea pasta according to package directions, reserving 1 tablespoon of pasta water before draining.
While pasta cooks, heat a non-stick skillet over medium-high heat and sear the diced chicken breast until golden and cooked through.
Remove chicken from the pan and add the sliced mushrooms and minced shallots, sautéing until the mushrooms are browned and tender.
Add the minced garlic to the skillet and cook for 30 seconds until fragrant, then return the chicken to the pan.
In a small bowl, whisk together the Greek yogurt, truffle oil, and reserved pasta water until smooth.
Lower the heat to low, add the cooked pasta and spinach to the skillet, and pour in the truffle yogurt sauce.
Toss everything gently until the spinach is wilted and the pasta is coated in the creamy sauce, then season with sea salt and black pepper.