In food processor with knife blade attached, blend flour with 1/4 cup olive or salad oil, 1 1/2 teaspoons salt, and 2/3 cup water, until mixture holds together and leaves side of processor bowl, about 15 seconds. With hands, shape dough into a smooth ball. (Or, in large bowl, stir flour, oil, salt, and water together to make a stiff dough. On lightly floured surface, knead dough until smooth and not sticky, about 5 minutes.) Cover dough with plastic wrap and let rest 30 minutes for easier rolling. Meanwhile, in small bowl, stir ricotta cheese, basil, black pepper, 3 tablespoons grated Parmesan cheese, and 1/4 teaspoon salt until blended. Divide dough in half. On lightly floured surface, with floured rolling pin, roll half of dough into about 15" by 12" rectangle. Spoon 12 dollops of ricotta mixture onto dough by level tablespoons, about 1 1/2 inches apart. Brush water on dough between dollops. Roll remaining dough into rectangle slightly larger than the first. Lift onto first rectangle to cover completely, pressing firmly between dollops and along edges to seal ravioli. With pastry wheel or knife, cut between dollops to make 12 ravioli. With pancake turner, lift ravioli onto lightly floured cookie sheet. Prepare spinach sauce: In 2-quart saucepan over medium heat, in 1 tablespoon hot olive or salad oil, cook onion until tender and golden. Add frozen creamed spinach and milk and cook, stirring frequently, until boiling. Stir in chopped tomato, 1 tablespoon grated Parmesan cheese, and 1/2 teaspoon salt; heat through. Keep warm. In 12-inch skillet over high heat, heat 1 1/2 inches water to boiling. Reduce heat to medium-high; add ravioli and cook, uncovered, 4 to 5 minutes until ravioli are tender but firm, stirring gently to separate pieces. Onto 4 warm dinner plates, spoon half of spinach mixture. With slotted spoon, arrange 3 ravioli on sauce on each plate, then spoon remaining spinach mixture over ravioli. Garnish with shaved Parmesan cheese and basil sprigs.
