In a small saucepan, bring the water to a boil over high heat. Add the lentils, reduce the heat to low, and simmer until most of the liquid has been absorbed, about 15 minutes. Keep an eye on them toward the end. Drain through a fine-mesh strainer.

In the meantime, add mushrooms and onions to the bowl of a food processor and finely chop. Heat the oil in a large frying pan over medium-high heat until shimmering. Add the onion and mushrooms and cook, stirring occasionally, until the vegetables soften and start to brown, about four to five minutes. Add the garlic and cook until fragrant, about 2 minutes.

Turn the heat down to low and add the tomato paste and stir it around until it loses its bright red color. Add in the paprika, oregano, and black pepper and stir to coat the onion mixture. Add the white wine, using a wooden spoon to scrape up any browned bits sticking to the pan. Simmer, turning the heat back up if necessary, until the wine has reduced and the mixture has thickened, about 3 minutes.

Remove from the heat and let cool slightly. Transfer the mixture to the bowl of a food processor fitted with a blade. Add the cooked lentils and vinegar, season generously with salt, and process until mostly smooth, with some small pieces remaining, about 1 minute.

Taste, season with additional salt and pepper as needed, and pulse to combine. Serve warm or cold over toast points, crostini, with crackers, pita chips, or raw or roasted vegetables. This is particularly good with roasted cauliflower.