Preheat your oven to 400°F and line a small baking sheet with parchment paper.
Place the cherry tomatoes on the sheet, drizzle with half of the olive oil and a pinch of sea salt, then roast for 12-15 minutes until they blister.
While tomatoes roast, bring a pot of salted water to a boil and cook the penne pasta until al dente, reserving 2 tablespoons of the pasta water before draining.
Season the chicken breast with sea salt and black pepper, then sear in a skillet with the remaining olive oil over medium-high heat until golden and cooked through.
Remove the chicken from the skillet, let it rest for 3 minutes, then slice it into thin strips.
Reduce the skillet heat to low, add the minced garlic, and sauté for 30 seconds until fragrant but not browned.
In a small bowl, whisk together the Greek yogurt, Parmesan cheese, and the reserved pasta water until smooth.
Add the cooked pasta, sliced chicken, and roasted tomatoes to the skillet, then pour the yogurt mixture over the top.
Toss everything together gently over low heat for 1 minute until the sauce is creamy and coats the pasta evenly.
Garnish with freshly chopped parsley and serve immediately.