Combine chicken, beer, oregano and bay leaf in a saucepan and bring to a simmer. Cook, covered, until chicken is no longer pink inside, 15 to 20 minutes. Let cool in liquid. Drain, discard bay leaf, and shred chicken (you should have about 2 cups).
Combine the chicken and Tomatillo Sauce. Season with salt and pepper.
72 calories;2 g fat(0 g sat); 0 g fiber; 3 g carbohydrates; 9 g protein; 4 mcg folate; 23 mg cholesterol; 1 g sugars; 0 g added sugars; 41 IU vitamin A; 3 mg vitamin C; 10 mg calcium; 0 mg iron; 93 mg sodium; 126 mg potassium