Season chicken with salt, pepper and garlic powder (about ¼ teaspoon salt and ⅛ teaspoon black pepper, and ¼ teaspoon garlic powder per chicken breast).
In a large skillet, heat about 2 tablespoons of olive oil over medium heat. Cook chicken, about 6 minutes per side, until golden brown and fully cooked through. Remove from skillet and set aside.
Don’t wipe the skillet clean. Add about 1-2 tablespoons of olive oil over medium heat. Add diced onions and cook for 2-3 minutes until softened, stirring occasionally. Add minced garlic and stir until fragrant, another 1 minute. Add white wine and scrape the brown bits from the skillet (this will release tons of flavor) and cook until the wine has reduced.
Stir in the cherry tomatoes and chicken broth. Cook for about 6-8 minutes, stirring occasionally, until tomatoes get soft. Break down the tomatoes using a fork and add more broth if needed. Add granulated sugar to help reduce the acidity. Then, season with Italian seasoning, salt and pepper to taste. Tip: If you want the sauce to be less chunky, cook it down 5-10 minutes longer adding more broth to taste.
Stir in chopped basil. Return chicken to skillet, nesting it under the sauce and spooning some over the top, and simmer for another 1-2 minutes.
Serve immediately with more basil on top and freshly grated parmesan cheese.
