Step 2 Heat oil in a deep skillet over medium heat. Add chicken; saute until no longer pink in the center and the juices run clear, 6 to 8 minutes. Remove chicken to a plate.
Step 3 Add shallot and garlic to the skillet and cook for about 2 minutes. Add tomatoes and cook 2 more minutes. Add condensed soup, chicken broth, and sour cream; stir to combine. Add spinach and cook for 5 minutes.
Step 4 Serve on plates and top with shredded mozzarella cheese.