Gather all ingredients: ripe tomatoes, arugula, red onion, and balsamic glaze.
Wash the tomatoes thoroughly under cold water.
Slice the tomatoes into halves or quarters, depending on their size.
Place the sliced tomatoes in a large mixing bowl.
Rinse the arugula and pat dry with a towel.
Add the arugula to the bowl with the tomatoes.
Thinly slice the red onion and add it to the salad.
Drizzle balsamic glaze over the salad for flavor.
Gently toss the salad to combine all ingredients.
Serve immediately on a chilled plate.