Heat 1 tablespoon of olive oil in a large skillet over medium heat until shimmering. Pat the chicken thighs dry, season with salt and pepper, and sear for about 5 minutes per side until golden brown. Remove and set aside.

In the same skillet, add the tomato sauce and minced garlic. Stir and bring to a gentle boil. Reduce heat to low, then pour in the heavy cream and stir to create a creamy sauce.

Fold in fresh spinach and basil into the sauce, stirring until spinach wilts, about 2-3 minutes. Taste and adjust seasoning if necessary.

Return the seared chicken to the skillet and cook for 5 additional minutes over low heat until heated through and no longer pink.

Plate the chicken topped with the creamy sauce and sprinkle with grated Parmesan cheese before serving.