Add olive oil to pan until hot and shimmering. Cook onion until soft, about 3-4 minutes. Add chard, cook 3-4 minutes until starting to soften. Add fire roasted chilis and toss.
In a small bowl, whisk together cumin, onion powder, salt, and pepper. Sprinkle over chard mixture and toss until well seasoned. Add cooked chorizo and toss. Turn down heat to medium-low and let simmer until chard has completely softened. Serve immediately.