In a small saucepan over medium heat, combine Guinness stout, ketchup, honey, balsamic vinegar, Dijon mustard, and minced garlic. Bring to a boil, then reduce heat to low and simmer for 15 minutes until thickened.

Heat cooking oil in a large frying pan over medium-high heat. Add chicken thighs and brown for 2-3 minutes on each side until golden.

Carefully drain any excess fat from the frying pan, then pour the thickened Guinness glaze over the chicken.

Cover the pan partially and cook uncovered for 15 minutes over medium heat, turning occasionally until the chicken is cooked through and the glaze is sticky.

Transfer the chicken to a serving platter and garnish with fresh herbs if desired. Serve with creamy mashed potatoes or roasted vegetables.