A great vegetarian main dish or side for a meal when fresh tomatoes are not available.
Heat 2 tablespoons of olive oil in the skillet and add the mashed or chopped garlic and the chopped onions. Cook on medium heat, stirring occasionally for 3 – 5 minutes, until the onion is transparent.
Before starting the cooking, put all the ingredients next to the pan on the stove, ready to go in at the proper moment. You remember the 10 Rules for Meal Preparation Success and mise en place, right?
Use a non-stick pot or large pan. I use my enamel-covered cast iron. Do not use "plain" cast iron as acid from tomatoes reacts with cast iron.
A wooden spoon is great for scraping up the bits of flour that tend to stick on the pan at the early stages.