Place 2 tablespoons olive oil in a large pot over high heat and add onions. Stir until they begin to soften, and then reduce heat to medium. Add garlic, cranberries, and remaining salt, pepper, and allspice. If mixture becomes too dry, add spoonfuls of reserved broth. Cook, stirring often, for another 5–10 minutes, until onions are tender. Add cooked quinoa and mix well. Remove from heat and stir in nuts, mint, parsley, and salt to taste.