Heat oil in a skillet set over medium. Add corn and cook about 5 minutes, until warmed and toasted.
In a large dish, arrange arugula. Pour cooked corn over the top, then add tomatoes, red onion, and goat cheese. Layer it pretty if you like.
Whisk together olive oil, red wine vinegar, dijon mustard, and salt and pepper until fully blended. Drizzle over salad just before serving and toss salad with tongs to mix.