Sprinkle seasoning mix and flour over the cubed meat; toss to coat.
Place 2 tablespoons olive oil in a large saucepan over medium-high heat; add meat, brown on all sides, stirring frequently; transfer beef and any juices to a plate or bowl; set aside.
Reduce heat to medium; add wine to hot pan, scraping up and keeping any remnants (deglaze); let wine gently bubble and reduce (in volume) by half.
Add butter, onion and garlic; stir and cook until vegetables are softened, ~5 minutes.
Add beef broth, Worcestershire sauce, thyme, rosemary, and garlic powder; bring to a bubbly boil.
Whisk together cornstarch and water; gradually add to pan, stirring continuously, until sauce thickens.
Reduce heat to low; add beef and its juices; simmer covered ~15 minutes; remove from heat and serve.
Nutrition Facts: Servings: 8; Amount per serving: Calories 602; Total fat 28.4g 43.7%; Saturated fat 13.1g 65.5%; Cholesterol 171mg 57.0%; Sodium 783mg 32.6%; Carbohydrates 49.7g 16.6%; Fiber 3.3g 23.6%; Sugars 5.1g 10.2%; Protein 35.8g 71.6%; Based on DV of 2000 calories per day