Marinate chicken breasts with salt, crushed garlic, 1 tsp olive oil, 1 tsp Balsamic vinegar, ½ tsp crushed peppercorns, rosemary and thyme. Mix and set aside for 10-15 minutes.
Combine mushrooms, red pepper, capsicum, yellow pepper, ½ tsp crushed peppercorns, salt, chopped garlic, remaining Balsamic vinegar, remaining olive oil and remaining crushed peppercorns in a bowl. Mix well and set aside to marinate for 5-10 minutes.
Heat 1 tsp oil in a non-stick grill pan. Place marinated chicken on it and grill till evenly done from both sides and chicken is cooked.
Heat remaining oil in another non-stick pan. Add marinated vegetables and sauté well.
To make dressing, combine Balsamic vinegar, olive oil, salt and crushed peppercorns in a bowl and mix well into a homogenous mixture.
Transfer sautéed vegetables in a bowl. Add 3-4 torn basil leaves and toss well. Cool to room temperature. Add torn Iceberg lettuce leaves, Lollorosso leaves and arugula leaves and mix well. Add some dressing and toss well.
Place the vegetable salad on a serving plate. Cut the grilled chicken into thick slices and place along the salad. Drizzle remaining dressing on top, garnish with some basil leaves and serve immediately.