Season chicken breasts with salt and pepper.
Sauté chicken breasts in ½ tablespoon oil in a very hot pan until golden brown. Flip over and cook other side until golden brown. Remove chicken from pan.
Add onion to same pan with remaining ½ tablespoon oil and sauté for 1 minute over high heat.
Add sliced mushrooms. Cook with the lid on until the mushrooms have released their liquid, about 5 minutes, stirring occasionally.
Remove the lid and cook until the liquid has evaporated and the mushrooms are a golden brown, about 5 minutes.
Add the sundried tomatoes, minced garlic, dried herbs, and bouillon cubes. Cook for 1 minute, breaking up the bouillon cubes.
Add the cream and 1 cup of water. Let simmer for 2 minutes.
Add the parmesan cheese and cook until melted, about 1 minute.
Turn off heat. Stir in basil.
Salt and pepper to taste.
Return chicken breasts to sauce and cook for just a few minutes until the breasts are done inside.