Boiling away the butter and seasonings from the leftover vegetables allows the flavors of the marinade to shine through. (If you don't have any leftover veggies, simply steam a mix of your favorites.)
Ingredients
8 cups assorted cooked leftover vegetables (such as carrots, green beans, cauliflower, and broccoli)
Place cooked leftover vegetables in large strainer. Lower strainer into large pot of boiling water until butter and seasonings are removed, about 30 seconds. Rinse with cold water; pat dry. Transfer to large bowl and mix in tomatoes.
Whisk all remaining ingredients in bowl; toss with vegetable mixture. Cover and refrigerate at least 6 hours and up to 2 days. Bring vegetables to room temperature. Season with salt and pepper; serve.