Slow-Cooker Beef Tacos with Rhubarb Salsa

Combine chili powder, oregano, cumin, garlic powder and 1 1/4 teaspoons salt in a small bowl. Sprinkle beef with 2 tablespoons of the mixture.

Heat oil in a large skillet over medium-high heat. Add the beef and cook, stirring occasionally, until browned on all sides, 5 to 6 minutes total. Place onion slices in a 5- to 6-quart slow cooker. Add the beef. Whisk broth and tomato paste into the remaining spice mixture and pour over the beef.

Cover and cook on High for 4 hours or Low for 8 hours. Shred the beef with 2 forks. Stir back into the liquid.

Meanwhile, toss rhubarb and sugar together in a medium bowl. Let sit for 10 minutes. Add bell pepper, jalapeño to taste, red onion, cilantro, lime juice and remaining 1/4 teaspoon salt and stir to combine.

Serve the beef with tortillas, the rhubarb salsa and lime wedges.