I agree that fresh beans work better. This can be done on top of the stove too.
Rinse the fresh beans and let them "drip" in a colander. Then put them in a bowl and microwave them (or steam them on a stovetop) for about 3 minutes. Lay them on paper toweling to absorb excess moisture.
Heat oil in a skillet and add the green beans. Let them sit and sizzle for a minute or so (this is where the crispness comes in). When you turn them over they will look a little brown from the caramelization. dont turn them too soon!
After you turn them, add fresh minced garlic and sea salt. GIve that side a minute or so and youre done.

There you have it. Crispy crunchy green beans.