- Prepare a large baking tray with a drizzle of olive oil. Set aside. 
- Chop the chicken breast into fillets, making sure they aren’t too thin. About ½-⅓  inch will be ok. 
- Then, beat the eggs in a medium-sized bowl, add ½ tsp salt. 
- Place breadcrumbs in another bowl. 
- Now, coat each chicken fillet with the egg mixture and then toss it in the breadcrumbs to coat. 
- Place the breaded chicken pieces on the prepared baking tray. 
- Set it aside and preheat the oven to 400F. 
- Prepare the sauce by placing the chopped onion in a medium-sized saucepan with a tbsp of the olive oil. 
- Sauté until translucent, then add the minced garlic and stir until fragrant. 
- Then add the tomato puree, dried Italian herbs, salt, and sugar. 
- Cover with a lid and simmer for about 5 minutes. Pro Tip: Longer simmering will result in better flavor as it reduces the acidity in the tomato puree. So if you have the time, add 1 cup of water and simmer until it has thickened again (about 20 minutes). 
- Once the oven reaches 400 degrees, bake the breaded chicken on one side for 8 minutes or until golden brown on the base. 
- Then, flip the chicken over and coat the pieces with the prepared tomato sauce, diced mozzarella, and shredded parmesan cheese. 
- Return it to the oven for another 8 minutes or until the cheese has melted and is slightly browned. 
- Serve warm with fresh basil leaves as garnish.