If you have 2 cups (480 ml) or more (or if you can supplement whatever you have with a little more tomato puree), use it the next day in a quick stir-fry. In a large sauté pan or skillet, heat a slick of vegetable oil over medium-high heat until it shimmers. Cut half a block of extra-firm tofu into cubes and add them to the oil in a single layer. Cook undisturbed until nicely browned on the bottom, then turn with a metal spatula and brown one or two other sides. Remove to a plate. Return the pan to medium-high heat and add a little more oil, along with whatever cut-up vegetables you’d like (try diced summer squash and small cauliflower florets) and a pinch of salt; sauté until just tender, then pour in the leftover sauce and bring to a simmer. Sprinkle in some frozen peas and frozen sweet corn, then return the tofu to the pan and heat through. Serve with rice.