Cook the pasta. Bring a large pot of salted water to a boil. Add pasta and cook according to package directions until al dente, usually 8 to 10 minutes. Drain well and set aside. While pasta cooks, prep the chicken and vegetables to save time.
Season the chicken. Pat chicken cubes dry with paper towels. In a bowl, toss chicken with 1 tablespoon olive oil, 1/2 teaspoon salt, black pepper, Italian seasoning, and smoked paprika until evenly coated.
Sear the chicken. Heat a large skillet over medium-high heat. Add the seasoned chicken in a single layer. Cook for 5 to 7 minutes, stirring occasionally, until golden on the outside and cooked through. Transfer chicken to a clean plate.
Roast the veggies. Toss cherry tomatoes, onion, and 1/2 teaspoon salt in a bowl, then spread on a rimmed baking sheet. Roast for 12 to 15 minutes, until the tomatoes start to blister and the onion is golden. Remove tomatoes and onions from baking sheet and set aside.
Make the sauce. In the same skillet, stir in 1/2 cup warm water, 1 cup chicken broth, and 1 cup Greek yogurt. Bring to a simmer over medium heat. Stir in Parmesan, lemon juice, and parsley. Cook for 1 to 2 minutes until smooth and slightly thickened (do not let it boil).
Combine everything. Add cooked pasta, roasted tomatoes and onions, and baby spinach to the sauce. Mix well to coat.
Divide into containers. Portion into 4 airtight meal prep containers. Store in the refrigerator for up to 4 days.