Add water, onion, celery, garlic, salt and pepper in a skillet over medium-high heat. Cook 9-10 minutes, stirring occasionally, until softened and turning golden. In a food processor, add chickpeas (except reserved 1/3 cup), lemon juice, tamari, sage, salt, and sautéed mixture, and partially puree (not fully like hummus, but leaving some chunkier consistency). Add toasted walnuts and oats, and briefly pulse to lightly break up nuts. Transfer to a bowl, and stir in spinach, cranberries, parsley, thyme, and reserved chickpeas. Transfer mixture to pie shell (or lightly oiled pie plate, see note), smoothing to evenly distribute. Brush tamari over top. Sprinkle on walnuts. Bake in preheated oven at 400 degrees for 30-35 minutes, until tart is golden on edges and top. Cool 5-10 minutes, then serve with cranberry sauce, a spoon drizzling of oil/balsamic vinegar slurry, or other sauce of choice. Serves 4-5.
Oats Note: The rolled oats, while lending some structure to the tart, can easily be omitted.
Pie Shell Note: This tart can be made without the pastry crust, if needed. If you want to make the tart without the crust, simply prepare the pie plate with a spray of oil (or wipe), and then bake for about 5 minutes less.
Nuts Note: For a nut-free option, use pumpkin seeds. You can reduce the amount in the filling if you prefer.
Note: Serve with Traditional Cranberry Sauce (below), or a gravy. Try Rosemary Gravy from LTEV or HOMESTYLE GRAVY, Plant-Powered Families. This recipe is also a reader favorite, from eat, drink and be vegan.