In a large lidded deep skillet or Dutch oven, heat the EVOO, three turns of the pan, and butter over medium-high. Once the butter is melted, add the shallots and a pinch of salt and black pepper. Cook, stirring, for 2 minutes. Add the Aleppo pepper, garlic, and paprika; stir for 1 minute. Add the tomato paste, stirring until coated, then pour in the wine. Stir in mussels and cover. Cook for 10 minutes or until mussels have opened (discard any mussels that do not open). Stir in the lemon juice and parsley and celery leaves. Taste and season with salt, if necessary. Serve with the crusty bread.