Evelyn's Spicy Italian Sausage and Zucchini

Heat a skillet over medium heat. Cook sausages in hot skillet, turning regularly, until no longer pink in the center, about 10 minutes. An instant-read thermometer inserted into the center should read 160 degrees F (70 degrees C). Transfer to a cutting board and slice.

Heat olive oil in a separate skillet over medium heat. Cook and stir onion, bell pepper, and garlic in hot oil until tender, about 5 minutes; season with red pepper flakes, salt, and pepper and cook 1 minute more. Add sliced sausage, crushed tomatoes, and sliced zucchini; bring to a boil, reduce heat to low, and continue cooking until the zucchini is tender, about 10 minutes.