In a large skillet, heat the EVOO over medium-high heat. Add the mushrooms and cook until softened, 8 to 10 minutes; transfer to a bowl. Add the onion, bell pepper, garlic, paprika, marjoram and coriander to the pan; season with salt and pepper. Cook until the vegetables are softened, 5 minutes. Stir in the cooked mushrooms, the Worcestershire sauce, tomato paste and hot sauce for 1 minute. Add the vegetable stock and cook until thickened, about 5 minutes.
Bring a large pot of water to a boil, salt it, add the pierogi and boil until they float, 7 to 8 minutes. Drain.
Heat another large skillet over medium heat. Add the butter to melt, then add the pierogi and cook until lightly browned. Stir in the chives and dill; season with salt and pepper. Serve the goulash and pierogi in shallow bowls with a dollop of sour cream.