Cook green beans in a large pot of boiling salted water until just crisp-tender, about 5 minutes. Using a large diameter strainer, transfer beans to a large bowl of ice water, cool completely. Drain well. (At this point you can make the beans a day ahead, store in refrigerator.) Alternatively you can steam the beans for 5 minutes and proceed directly to the skillet.
Melt 1/4 cup of butter in a heavy large skillet over medium hight heat. Whisk in 1 Tbsp of fresh thyme, 1 Tbsp of mustard and 1 teaspoon of garlic salt into butter. Add beans to skillet and toss until heated through, about 4 minutes. Transfer to serving bowl. Sprinkle with toasted almonds and remaining 1 Tbsp of thyme.