Heat olive oil in a large skillet over medium heat. Season chicken with salt, pepper, and oregano. Cook until golden and fully cooked (internal temp 165°F), about 8 minutes per side. Remove and set aside.
In the same skillet, melt butter. Add garlic and cook until fragrant.
Add cherry tomatoes, season, and cook until they begin to soften and burst.
Stir in spinach and cook until wilted.
Add heavy cream and Parmesan, bringing to a gentle simmer.
Return chicken to the skillet and simmer until heated through and coated in sauce.
Serve Creamy Tuscan Chicken with lemon wedges for a fresh finish.