Slice the lemon crosswise into round "wheels", making each as thin as possible. Remove all seeds. Mix the soy sauce, triple sec, cumin powder, and garlic powder in a small bowl. Soak the lemon wheels in the soy mixture and set aside for later use.
Preheat a large covered cooking pan, to medium heat. Dice shallot. Mince garlic cloves. Melt butter in cooking pan. Add diced shallot and then a few minutes later add minced garlic to buttered pan. Cook shallot and garlic until golden brown.
Add chicken breasts to cooking pan. Add lemon and soy mixture, making sure chicken gets soaked with soy. Add olive oil and black pepper. Splash dish with white wine, cover, and apply medium-high heat. Keep dish covered while cooking. After 5 minutes add capers. (Drain vinegar before adding.) Turn chicken occasionally, keeping moist. If dish gets too dry, add another teaspoon of olive oil, as necessary. Serve immediately when chicken is cooked through, about 12-15 minutes.
Keep the chicken breasts thin. The thicker the chicken breast, the longer it will take to cook, and unfortunately the drier the chicken breast will become as a result of the triple sec and wine. Keep chicken breasts covered during cooking.
Lemons should be kept thin also, the thinner the better. It is best to select a soft, ripe lemon with a thin rind. Meyer lemons have exceptionally high sugar content and are ideal for this dish.
The best capers are large whole pickled capers, often Spanish in origin. The are about the size of a large thumbnail and have a long stem. If large capers aren't available, use the smaller variety (about the size of a pinky nail or smaller) but use 1/4 cup instead of 1/2 cup. Most supermarkets stock jars of capers near their traditional cucumber pickles or in the imported foods section.
Enjoy this dish with a shiraz / syrah.