1. Preheat oven to 325 degrees. In a small bowl, whisk together mole sauce and 1/2 cup water until smooth.

2. In a large heavy-bottom saucepan with a tight-fitting lid, heat oil over medium-high. Season turkey with salt and pepper; cook, rounded side down, until browned, about 5 minutes. Turn breast; pour mole mixture over turkey.

3. Cover tightly; bake until turkey is no longer pink in the middle (an instant-read thermometer inserted in the thickest part should register 165 degrees), about 40 minutes. Transfer turkey to a cutting board; let rest 10 minutes before thinly slicing.

4. Stir sauce in pan to combine; serve with turkey. Garnish with sesame seeds, if desired.