Here's What You'll Need
olive oil, balsamic vinegar, dijon mustard, lemon, sugar, salt, pepper, pasta, tuna fish, cherry tomatoes, baby arugula, dill, chives
Combine olive oil, balsamic vinegar, Dijon, lemon juice, sugar, salt, and pepper in a measuring cup, then whisk to combine. Set aside.
Preheat an oven to 425F. Place the tomatoes on a rimmed baking sheet, then drizzle with olive oil and salt, then roast for 15 minutes.
Bring a large pot of salted water to a rapid boil, then add pasta. Cook according to package directions until just past al dente, but not mushy. Drain the pasta.
Place pasta in a bowl, then pour balsamic vinaigrette on top. Add cherry tomatoes, arugula, tuna, dill, and chopped chives. Carefully toss to mix well.
You can enjoy right away or chilled for at least 2 hours. Can be served cold or at room temperature. Before serving, add another handful of baby arugula and sprinkle with flaky sea salt.