Heat two tablespoons of the olive oil in a large heavy pot or Dutch oven over medium-high heat. Add the mushrooms in a single layer and cook without stirring for three to four minutes, until the undersides are deeply golden. Stir, cook two minutes more, then transfer to a plate. Working in batches keeps them from steaming, which is what gives the pot its savory base.

Lower the heat to medium and add the last tablespoon of oil. Add the onion and bell peppers and cook for six to seven minutes, until softened and just starting to color. Stir in the garlic and caraway seeds and cook for thirty seconds, until fragrant.

Pull the pot off the heat. Add the sweet paprika, smoked paprika, and tomato paste, and stir constantly for about thirty seconds; the residual heat blooms the spices without scorching them. This is the step that decides the final flavor, so do not rush it or let the paprika sit on direct high heat.

Return the pot to medium heat and pour in the red wine, scraping up any browned bits from the bottom. Let it bubble for a minute, then stir in the soy sauce, marjoram, bay leaves, diced tomatoes, potatoes, and vegetable broth.

Bring to a boil, then reduce the heat to low, cover, and simmer for thirty to thirty-five minutes, until the potatoes are tender but still hold their shape. Stir once or twice and add a splash more broth if it looks too thick before the potatoes are done.

Return the browned mushrooms to the pot along with the lentils. Simmer uncovered for five more minutes to warm them through and let the stew thicken slightly. Remove the bay leaves, stir in the red wine vinegar, and taste for salt and pepper. Ladle into bowls and finish with fresh parsley.