1. Place onion in sluggish cooker. Organize brisket over onion (tucking edges underneath to suit, if vital). Sprinkle with salt and pepper; prime with 1/3 cup chili sauce. Cowl; prepare dinner on excessive 3 1/2 hours.
2. Mix remaining 1/3 cup chili sauce, brown sugar, and cinnamon in massive bowl. Add candy potatoes and prunes; toss to coat. Spoon combination over brisket. Cowl; prepare dinner on excessive 1 1/4 to 1 1/2 hours or till brisket and candy potatoes are tender.
3. Switch brisket to slicing board; tent with foil. Switch candy potato combination to serving platter, leaving juices in sluggish cooker. Preserve heat.
4. Mix cornstarch into water in small cup till clean. Stir combination into sluggish cooker juices. Cowl; prepare dinner on excessive 10 minutes, or till sauce thickens.
5. Reduce brisket crosswise into skinny slices. Serve with candy potato combination and sauce.
