Preheat the oven to 425°F.
Pat the chicken breast dry and season with salt and pepper.
Prepare a dredging station by whisking the egg white in a shallow bowl. In another dish, combine the almond flour and grated Parmesan along with a pinch of salt, pepper, and chopped fresh basil if desired.
Dip the chicken breast first in the egg white, then thoroughly coat in the almond flour and Parmesan mixture.
Place the coated chicken on a baking sheet lined with parchment paper. Lightly spray or drizzle a bit of olive oil over the chicken.
Roast the chicken in the oven for about 18-20 minutes, or until the internal temperature reaches 165°F and the coating is crispy.
Meanwhile, toss the broccolini with a drizzle of olive oil, salt, and pepper. Spread it on another baking sheet.
Roast the broccolini in the oven for about 12-15 minutes, until tender and slightly crispy on the edges.
Warm the tomato sauce in a small saucepan over low heat and season with a bit of basil, salt, and pepper.
Plate the chicken, spoon the warm tomato sauce over or alongside it, and add the roasted broccolini. Garnish with extra fresh basil if desired.