Slice the chicken breast into 1cm thick pieces.
Mince the garlic.
In a bowl, mix the sliced chicken breast, minced garlic, olive oil, salt, and pepper, then marinate for 10 minutes.
Add olive oil to a pan and lightly sauté the garlic.
Place the marinated chicken breast on the pan and cook both sides.
Spread mustard sauce and yogurt sauce on bread (such as rye or whole wheat bread).
Top the bread with cooked chicken breast, lettuce, and sliced tomato.
Cover with another slice of bread to finish.