For the relish, in a large bowl, whisk together the vinegar, oil and sugar. Add vegetables to bowl and toss with dressing and celery seed; season with salt and pepper. Let the relish stand 30 minutes. Drain.
In a cast-iron or other deep skillet, heat the oil over medium-high. Melt the butter into the oil. When the butter foams, add the meat; season with salt and pepper. Cook, breaking the meat up with a spoon, until brown, about 10 minutes.