Preheat oven to 375 degrees. In a large, hot nonstick pan (oven-proof), coat with olive oil and saute chicken/vegetable mix, tomatoes and scallions. Lightly mix eggs and cream together and add to pan. Season and stir once to get eggs cooking. Top with cheese and place in oven, 20 minutes until it puffs up. If necessary, turn broiler on and brown the top. Let stand 5 minutes, then slice and serve. For the salad, whisk together shallots, mustard and vinegar. Drizzle in oil and season. Add bibb and toss lightly. Check for seasoning.
PLATING: Place slice of frittata on plate next to the salad. Garnish with chives.