In a large saute pan, melt the butter over medium-high heat. Add the garlic and cook, stirring, until fragrant, about 1 minute. Add half of the kale and sauté, stirring frequently until it begins to wilt, about 2 minutes. Stir in the remaining kale and repeat. Add the broth, the 1/2 tsp. salt and the 1/4 tsp. black pepper. Stir in the lemon juice. Simmer, stirring occasionally, until the kale softens, about 6 minutes.