Start by washing and trimming the green beans. Dice the onions, slice the garlic, and chop the tomatoes. I like to keep everything ready before heating the pan—it makes the cooking process smooth and stress-free.
Heat olive oil in a large pot and add garlic and onions. Sauté until they become fragrant and translucent, about 5 minutes. This step builds the base flavor for the stew, so don’t rush it.
Add the green beans and diced tomatoes to the pot. Stir to combine, cover, and let cook for 5 minutes. This helps the green beans soften slightly before adding the tomato sauce.
Pour in the tomato sauce, stir, reduce the heat to low, and cover the pot. Let it simmer gently for 40 minutes, stirring occasionally. This slow cooking allows the beans to absorb the rich tomato flavors perfectly.
Once the beans are tender, stir in salt, red pepper flakes, and lemon juice. Cover and cook for an extra 5 minutes. Taste and adjust seasonings as needed before serving.