Rinse green beans in water. Remove it onto a plate.
Trim off the stem edge of the beans. I did not trim both the ends, I left thin string side. It’s edible to eat and leaving it on the beans makes it look beautiful. With tender and crispy beans, the string ends wont really bother you. But if you are not a fan, go ahead and trim both ends.
Bring about 5 qt water to boil. When water starts boiling, add kosher salt (to taste) into boiling water.
Add all the green beans into the boiling water. Blanch it for about 3 to 5 minutes. We do not want to over cook beans. It needs to be just cooked/blanched but still have that crunch.Note : I like crunchy beans so always cook to the point it has that crunch but cooked (not fully cooked). Cook longer if you prefer fully cooked beans. Start with cooking for 7 to 9 minutes. Check if it's cooked. Cook longer if needed.
Remove blanched beans immediately into ice bath and let it cool completely. Drain if off and keep aside.
Melt butter in a skillet.
Add minced garlic and cook stirring until golden brown. This step is important. Do not rush to add the blanched green beans into skillet. Wait until garlic is golden brown. Browning garlic ensures maximum flavors of the garlic in the dish. Don't rush this step.
Next add salt and pepper to taste.
Throw in the blanched green beans into skillet. Toss well to ensure all the beans are coated with butter and seasoning. Toss and cook for 3 minutes. We want to have green beans cooked and still have that crunch.
Add lemon juice. Turn off stove. Toss the skillet to coat sautéed green beans.
Transfer beans onto serving plate.
Grate Parmesan cheese and zest of 1 lemon over sautéed green beans.
Serve immediately as sides for Thanksgiving dinner.