1. Heat 1 tablespoon of olive oil over medium heat in a large, wide saucepan or lidded skillet. Add onion and pine nuts. Cook, stirring, until the onion is tender and beginning to color (5-8 minutes). Add the garlic. Cook, stirring, until fragrant (30 seconds).
2. Stir in the currants, cinnamon, allspice, and sugar. Add 1/2 cup water and cook, stirring, until most of the liquid has evaporated (5-6 minutes). Add barley and pepper to taste. Remove from the heat and stir in the herbs.
3. Stuff the peppers with the barley mixture. Stand the peppers in a wide, lidded pan. Mix together the remaining 2 tablespoons olive oil, 1/2 cup water, and lemon juice, and pour around the vegetables. Bring to a simmer and cover the pan. Simmer on medium-low, adding water as needed, until the peppers are very tender and there is just a small amount of liquid left (40-50 minutes). Garnish with lemon wedges to serve.