Cook shells in boiling water until just tender. Drain and set aside.
To prepare Ricotta, press tofu with a weight for ½ hr. to drain. Crumble tofu with hands and add remaining “ricotta” ingredients. Mix garlic, herbs, tahini, salt & pepper with chopped spinach and fill shells with mixture.
Spoon layer of pasta sauce into bottom of roasting pan, arrange shells, and top with remaining pasta sauce.
Bake at 350 degrees, covered for 25 minutes. Garnish with chopped parsley.