Heat olive oil in a large skillet over medium heat. Add the garlic and cook, stirring often, for 1 minute. Add the tomatoes, lima beans, corn, and bell pepper and cook for 3-5 minutes until tomatoes soften and beans are just tender.
Remove from heat and place in a serving bowl. Stir in the chopped scallions.
Place the white balsamic vinegar, honey, garlic, rosemary, onion, mustard, salt and pepper in a food processor or blender and pulse to combine. With the blade running, gradually add in the olive oil in a slow, steady stream until smooth. Toss with the succotash and serve.