How to Make It
In a deep, medium skillet, melt 1 tablespoon of the butter in 1 tablespoon of the oil. Add the onions and cook over high heat, stirring, until softened, about 5 minutes. Reduce the heat to moderately low and cook, stirring occasionally, until browned, about 30 minutes; add a little water to the pan if the onions seem dry. Season with salt and pepper.
Meanwhile, roast the bell peppers directly over a gas flame or under the broiler until soft and charred all over. Transfer the peppers to a bowl, cover with plastic; let stand for 15 minutes. Peel, core and seed the peppers and cut them into 1/2-inch strips. In a bowl, toss the peppers, dates, sesame and poppy seeds with 1/2 tablespoon of the olive oil. Season with salt and pepper.
Spread the onions on the pitas and top with the red pepper mixture. Quarter the pitas and arrange on a platter.
Dredge the cheese in the flour and shake off any excess. In a medium nonstick skillet or grill pan, melt the remaining 1 tablespoon of butter in the remaining 1 tablespoon of oil. Fry the cheese over moderately high heat, turning once, until golden, 4 minutes. Top each tart with 2 pieces of fried cheese and serve.