A recipe from a friend who says she copied it from Martha Stewart
4 boneless, skinless chicken breast halves (about 1 1/2 pounds)
Salt and black pepper , to taste
1 TBSP olive oil
1 lb mushrooms, trimmed and quartered
2 garlic cloves, minced
1 14.5 oz can diced tomatoes
1/4 tsp dried oregano
Season chicken with salt and pepper. In a large saucepan with a tight-fitting lid, heat oil over medium-high heat; swirl to coat bottom of pan. Cook chicken, turning when it easily releases from the pan, until golden, 4 to 6 minutes. Transfer to a plate.
Add mushrooms; and cook until softened, about 5 minutes. Add garlic, tomatoes, and oregano. Bring back to a boil. Return chicken and any accumulated juices to pan; cover, and cook until chicken is tender (about 10 to15 minutes). Turn chicken to coat with sauce, and serve.