To a large pot of boiling, salted water, add green beans, and cook for 2 minutes. Drain beans, pat dry, and place in a large bowl. Add tomatoes, onions, and feta cheese.
In a small bowl or jar with a lid, add lemon juice, olive oil, dijon mustard, garlic, salt, and pepper. Whisk or mix together. Pour dressing over vegetables and toss. Taste and adjust seasoning. Let marinate 15 minutes and serve.
Notes
Recipe Variations:
Add Nuts: Try adding toasted almonds, walnuts, or pine nuts for a crunch and nutty flavor.
Try a Different Cheese: Goat cheese crumbles make a nice, creamy substitute for feta.
Add Fresh Herbs: Chopped basil or parsley can add a fresh, herbaceous twist.
Roasted Vegetables: Roasted red peppers or zucchini would be excellent additions to this salad.