In a large saucepan, bring 2 cups of water to a boil; add groats. Reduce heat and simmer, uncovered and stirring occasionally, until tender and no water remains, about 45 minutes.
Drain and rinse under cold water; drain again.
Honey-Lime Vinaigrette: Meanwhile, whisk together oil, lime zest, lime juice, honey, chili powder, salt, and pepper.
In a large bowl, combine groats, black beans, tomatoes, jalapeño pepper, and onion. Add vinaigrette and toss to coat. Cover and refrigerate for 1 hour. (Make-ahead: Refrigerate in an airtight container for up to 24 hours.)
To serve, stir in avocado and sprinkle with cilantro.
