In a large skillet, over medium heat, cook the chopped pancetta until crisp, about 5 minutes. Remove from the skillet to a paper towel lined plate, and set aside.
In a large shallow bowl (or plate), add the bread crumbs and grated cheese and mix to combine.
In another large shallow bowl, add the egg and lightly beat.
Make an assembly line, first dipping your chicken breast half into the egg, then the bread crumb mixture to fully coat. Repeat until you're out of chicken.
In the same skillet you used for the pancetta, heat 2 Tablespoons of the olive oil over medium high heat then add chicken, cooking approximately 4 minutes on each side, or until fully cooked. Remove from the pan and add a tin foil tent to keep it warm.
Again, in the same skillet, add the remaining Tablespoon of olive oil and garlic and cook for about 30 seconds or until fragrant.
Add in the spinach and season with salt and pepper. Use tongs to cook, tossing it until it's wilted. Remove and keep warm.
In that same skillet, add half of the cooked pancetta and the jar of marinara sauce. Bring to a simmer over medium heat.
While that is warming, slice your cooked chicken.
Scoop a half cup of sauce onto your plate then top with the sliced chicken and spinach. Drizzle with more sauce and garnish with remaining pancetta.