In a medium pot, bring generously salted water to a boil.
Meanwhile, set up the ice bath: In a large bowl, combine water and ice (enough water to fully submerge the green beans and enough ice to keep the water ice cold). Set aside.
Cook green beans for 5-6 minutes in the boiling water or until they are crisp tender and bright green. Drain and transfer to the prepared ice bath. You could also transfer them straight from the pot using tongs. Let them get fully cold, about 5-8 minutes. Then, remove green beans from the ice bath and pat dry with paper towel.
In a large skillet, cook the bacon until crispy. Then, transfer to a plate lined with paper towel and chop. Set aside. Leave about 2 to 3 tablespoons of the bacon fat in the skillet.
Add garlic and shallots to the skillet with the bacon fat, and cook until fragrant and slightly golden brown for about 2 minutes over medium-high heat.
Add the green beans and bacon to the skillet, and cook for another 2 to 3 minutes, tossing until coated and warm. Season with salt, pepper and red chili flakes to taste. Serve warm. Enjoy!