Bring a large pot of salted water to a boil and cook the red lentil penne according to package directions, reserving 0.25 cup of pasta water before draining.
While the pasta cooks, heat the olive oil in a large skillet over medium-high heat and add the diced chicken breast, seasoning with sea salt and black pepper.
Sauté the chicken until golden and cooked through, then remove from the pan and set aside.
In the same skillet, add the sliced cremini mushrooms and minced shallots, cooking until the mushrooms are browned and tender.
Stir in the minced garlic and cook for 30 seconds until fragrant, then reduce the heat to low.
Whisk the Greek yogurt with the reserved pasta water until smooth, then pour the mixture into the skillet along with the cooked pasta and chicken.
Toss all ingredients together until the sauce is creamy and coats the pasta evenly.
Remove the skillet from the heat, drizzle with truffle oil, and garnish with fresh chopped parsley before serving.