Prepare Ingredients: Gather all ingredients. Fill a big pot with salted water and bring to a boil on high heat.
Cook Beef: Heat a large skillet over medium heat. Add chopped beef and cook, stirring occasionally, until rendered and crispy, about 8 minutes. Using a slotted spoon, transfer beef to a paper towel-lined plate to drain, reserving about 3 tablespoons of drippings in the skillet.
Cook Chicken: While beef cooks, sprinkle chicken evenly with pepper and ¼ teaspoon of the salt. Add chicken to the skillet with drippings; cook over medium-high heat until browned and cooked through (internal temperature of 165°F), 5 to 6 minutes per side. Transfer chicken to a plate; set aside until cool enough to handle, about 10 minutes. Chop chicken into bite-sized pieces.
Prepare Sauce Base: Reduce heat to medium and add sun-dried tomatoes and shallot to the skillet. Cook, stirring often, until softened, about 2 minutes. Add garlic, Italian seasoning, crushed red pepper, and remaining 1 teaspoon salt. Cook, stirring constantly, until fragrant, about 30 seconds. Cook for about 1 minute, stirring regularly, until the tomato paste has deepened in color.
Finish Sauce: Pour in chicken broth; cook, stirring and scraping constantly to deglaze the skillet, about 1 minute. Stir in cream and bring to a simmer over medium heat. Cook, stirring periodically, until somewhat thickened, 3 to 5 minutes.
Cook Tortellini: Add tortellini to boiling water and cook until tender and floating, 3 to 5 minutes. Reserve 1 cup of cooking water. Drain tortellini.
Combine and Serve: Stir Parmesan cheese, reserved cooked beef, chopped chicken, and tortellini into the skillet with the cream mixture. Cook, turning and tossing frequently, until evenly coated with sauce. Add reserved cooking water, ¼ cup at a time, if necessary, to maintain a creamy consistency. Divide among 6 bowls; garnish with additional Parmesan cheese and fresh basil.