Butterfly chicken breast then separate so you have 4 individual breasts lightly pounded.
Lightly flour breasts then shake off any excess flour.
Generously salt and pepper breasts on both sides.
Heat olive oil and butter in large cast iron skillet over med/high heat.
When oil/butter combo is ready, very carefully place chicken breasts in pan.
Saute about 5-6 minutes on 1st side then flip over and cook 2nd side another 4 minutes (if breasts are too thick they may need longer cooking time).
Add a couple of splashes of white wine during last 2 minutes of cooking.
When done, remove breasts to separate plate and cover with foil to keep warm.
While breasts are cooking , quickly dice up your veggies (cut zucchini in half lengthwise then each half in half again then slice into bite-size pieces, thinly slice mushrooms, cut tomatoes into same size as zucchini).
Reduce heat under pan to medium then add veggies and tomatoes along with capers, lemon juice & garlic (if needed add more butter).
Saute mixture until zucchini is cooked but still has has bite to it-do not overcook the veggies (10 minutes max).
Just before serving, add 2 tablespoons milk to sauce to make a more gravy-like texture.
Plate rice with chicken breast then cover with veggie sauce.