Add the onion, garlic, and measured salt and pepper and cook, stirring occasionally, until the onion is softened and beginning to brown, about 8 minutes.Increase the heat to high, add the water, and bring to a boil. Stir in the greens a handful at a time, adding more as they wilt, until they’re all in the pot. Cover with a tightfitting lid, reduce the heat to low, and simmer, stirring occasionally, until the greens are tender but not mushy, about 25 minutes.Uncover the pot, add the remaining ingredients, and stir to combine. Cook, stirring occasionally, until the cheeses are melted and combined and the mixture is heated through, about 4 minutes. Taste and season with salt and pepper as needed.