Boil a pot of salted water and cook the chickpea pasta according to package directions until al dente; reserve 2 tablespoons of pasta water before draining.
While pasta cooks, season the chicken breast with half the salt and pepper, then sear in a pan with olive oil over medium-high heat until golden and cooked through.
Remove chicken from the pan, let it rest for 3 minutes, then slice into thin strips.
In the same pan, add the sliced mushrooms and shallots, sautéing until the mushrooms are browned and the moisture has evaporated.
Add the minced garlic to the pan and cook for 30 seconds until fragrant, then deglaze with the vegetable broth.
Toss the cooked pasta, sliced chicken, and reserved pasta water into the pan with the mushrooms.
Remove from heat and drizzle with truffle oil, then toss well to coat every strand in the aromatic sauce.
Serve immediately topped with grated parmesan cheese and fresh parsley.