CLEAN COLLARD GREENS: Remove any yellow or limp leaves when separating the bunch of collard greens. Submerge the leaves in a large bowl of cold water and swish them around vigorously. Then, remove the leaves from the water and re-fill the bowl with clean water, repeating this process 2 to 3 times, or until grit comes off. Pat dry, or spin the greens until dry.
CUT COLLARD GREENS: Cut off the tough stems and then the center veins. Sort and place leaves of similar size together in a pile, roll them tightly like a cigar, and thinly slice them (chiffonade) crosswise into about 1/4-inch wide strips.
TENDERIZE GREENS: In a medium pot, bring 6 cups of water to a boil over high heat. Place the cut leaves into a colander. Pour the boiling water over the leaves to slightly wilt them and then drain well to remove all the excess liquid (you can shake the colander or press down gently on the greens with a spoon).
COOK COLLARD GREENS: If making with bacon (couve a mineira com bacon), cook the diced bacon in a large, heavy skillet over medium heat until there are no more pink, white, or translucent areas on the bacon, about 5-7 minutes. If needed, add 1 tablespoon of oil in order to add garlic and cook, stirring often, until fragrant, about 60-90 seconds.
If not cooking with bacon (couve a mineira sem bacon), skip that step and cook garlic with oil over medium heat. Add greens and sprinkle salt, pepper, and the bouillon powder (optional). Cook, stirring often, for about 2 to 3 minutes or until greens are tender but still bright green. Taste and adjust seasonings if needed. Serve garlicky collard greens warm!