Coat the chicken with the balsamic, EVOO, seasoning and rosemary and set aside.
In a skillet, add the chopped bacon – work in two batches if preparing salad for four. Brown the bacon over medium-high heat, then transfer the bits to a paper towel-lined plate to drain. Using center-cut bacon will cut down on the pan drippings that spatter.
Coarsely chop the spinach leaves and add them to the salad bowl. Top with the mushrooms, radishes and scallions. Season the salad with salt and pepper.
Wipe out the bacon pan and return to stove, turning the heat back to medium-low. Add 1 tablespoon EVOO for your dressing and the shallots and reduce the heat to medium. Sauté the shallots for 3 minutes. Remove the EVOO and shallots from heat.
In a bowl, combine the mustard and balsamic vinegar. Slowly stream in 2/3 cup EVOO while whisking the dressing to emulsify it. Add the warm shallots and toss with the spinach salad to coat evenly. Add the cooked bacon and toss again.
Pre-heat a nonstick skillet over medium-high heat. Cook the chicken cutlets, 4 minutes on each side, in a single layer. Slice the breasts on an angle on your cutting board once they are all out of the pan. Pile the spinach salad on to dinner plate/plates. Top each salad with two sliced chicken cutlet pieces.