Bring the 2 1/4 cups water and the 2 cups vegetable broth to a boil in a pressure cooker. Add the polenta while stirring. Stir in the garlic and basil, lock the lid in place, and bring to high pressure. Reduce heat but maintain high pressure for 5 minutes. Remove from heat and let pressure come down naturally. Stir well, salt to taste, and keep warm until ready to serve. (No pressure cooker? See note below)While the polenta is cooking, sauté the onion in a medium-sized sauce pan until it begins to soften, about 3 minutes. Add the garlic and drained chickpeas and stir for another minute. Add the broth, basil, and pepper. Reduce heat to low and simmer for 5 minutes. Add the lemon peel and juice. Mix the arrowroot or cornstarch with 1/4 cup water and add it to the pan. Cook over medium low heat until slightly thickened. Keep warm.Bring a large pot of water to a boil and blanch asparagus for 2 minutes. Drain well and toss with a squeeze of fresh lemon juice, 1 teaspoon of lemon zest, and coarse salt to taste. Divide the polenta among 4 plates, and top each with a quarter of the chickpeas and asparagus. Sprinkle 1 teaspoon of toasted pine nuts over each serving.