Slow Cooker Beef Stew With Maple and Stout

large carrots, peeled and cut into 1 1/2-inch chunks

large parsnips, peeled and cut into 1 1/2-inch chunks

large russet potatoes, peeled and cut into 1 1/2-inch chunks

thyme sprigs

rosemary sprigs

to 3 ½ pounds chuck roast, excess fat trimmed, cut into 2-inch chunks

stout beer

maple syrup, preferably dark

garlic cloves, chopped

onion powder

garlic powder

balsamic vinegar, preferably aged

Kosher salt and black pepper