Cut ends off green beans, and then cut beans at an angle into about 2" pieces. For most green beans, you will get 2-3 pieces out of each bean. Rinse thoroughly and drain well
Cut the stems off mushrooms. You want all of the mushrooms to be about the same size, so they cook at the same time. If you can find mini baby portobellos, leave them whole. Otherwise, cut each mushroom in half. DO NOT rinse mushrooms or they will absorb too much water. If you need to clean mushrooms, use a damp cloth to wipe off excess dirt.
Add sliced almonds to large, dry non-stick skillet over medium heat. Toast almonds until golden brown. Watch carefully, or they will burn. Remove and set aside
In same skillet, melt butter over medium heat. Add onions and a pinch of salt, and cook slowly for about 7 minutes, stirring occasionally, until the onions are golden. Add garlic and cook for 2 minutes
Turn heat to medium high, and add green beans. Season with salt, pepper, onion powder & garlic powder. Cook for about 5 minutes, tossing occasionally so beans don't scorch.
Reduce heat to medium low. Add mushrooms and white wine, toss together and cook for about 5 minutes. The alcohol will cook out, leaving just great flavor.
Add toasted almonds, toss together, portion into a large serving container, and serve