Set aside ¼ cup of the marinade. Place remaining marinade and chicken breasts in a shallow dish, cover and refrigerate 30 minutes.
Heat oven to 400°. On a baking sheet, toss tomatoes, olive oil, 1/4 tsp of the salt and the pepper. Roast at 400° for 15 minutes, until tomatoes are softened and slightly charred.
Heat a grill pan over medium heat. Coat pan with nonstick cooking spray. Remove chicken from fridge; discard marinade and season chicken with remaining salt. Cook breasts, 4 at a time, until cooked through, 5 minutes per side.
Transfer 4 chicken breasts to a container with a tight-fitting lid. Refrigerate for Wednesday.
Spoon quinoa into a large glass bowl. Microwave until warm, 3 minutes. Stir in reserved marinade, roasted tomatoes and arugula. Serve with chicken breasts. Garnish with lemon wedges.