The beer doesn't need to be green on St. Patrick's Day when you're cooking up a batch of dark leafy greens.
Heat oil over medium heat in a large, deep pan. Add leeks and sprinkle with salt. Cook until leeks soften, about 5 minutes. Add garlic and cook until fragrant, about 2 minutes.
Add the greens, starting with cabbage, then kale, and finish with chard on top because it is the most tender of all three. Cook for about 10 minutes, until greens have wilted down. Add the ale and simmer 10 minutes, or until most of the liquid has evaporated. Remove the pan from the heat and stir in lemon juice. Season with more salt and pepper, if desired.