In a large bowl, whisk together cornstarch, salt, pepper, and thyme.
Stir in beef cubes to coat.
Heat oil in a 4 ½-quart Dutch oven over medium-high heat. Brown meat in four batches and set aside.
When finished, return all meat to Dutch oven and add apple cider, vinegar, and water. Cook, stirring to scrape bits off the bottom, until it comes to a boil.
Place chopped vegetables and apple in the bottom of slow cooker.
Pour meat mixture over top. Turn to low setting and cook for 6 to 8 hours or 3 hours on high.