My husband, too, loves green beans when they are al dente. Both of us remember the mushy boiled ones from our childhoods. To get the proper tenderness with some "bite" to it, I stir-fry them. I use peanut oil, but any oil will do. Just get the pan really hot over medium-high heat, THEN add the oil. When the oil is "shimmering" but not smoking, add the green beans. Just a few minutes of stir-frying and they will be ready to eat. (You don't need a wok. In fact, woks are NOT the best thing for stir-frying in Western kitchens. They were designed to accommodate the EASTERN method of cooking. Just use a saute pan.)

If you want to add minced garlic, do it a few seconds before you add the green beans. Any liquids that you want to add, or sauces that you like should be added after the beans are cooked, just before taking them off the stove and serving. They are really dead easy to cook properly.