Nutrition per serving may change if servings are adjusted.
3 medium red potatoes, scrubbed and quartered (about 8 ounces total)
1/4 cup red- or white-wine vinegar, divided
2 tablespoons extra-virgin olive oil, divided
Salt & freshly ground pepper to taste
8 ounces green beans, ends snapped
8 ounces tuna steak, cut into 1/4”-thick slices
2 cloves cloves garlic, minced
2 anchovy fillets, rinsed and minced, or 1 teaspoon anchovy paste
1/4 cup reduced-sodium chicken broth
1 1/2 teaspoons Dijon mustard
1 large red bell pepper, roasted (see Tip) and cut into thin strips
2 tablespoons capers, rinsed
Lemon juice to taste
Place potatoes in a steamer basket over boiling water. Cover and steam until tender, 10 to 15 minutes. Transfer to a serving bowl, reserving steaming water. Add 1 tablespoon vinegar and 1 tablespoon oil and toss gently. Season with salt and pepper and set aside. Place green beans in the steamer basket, cover and steam until tender, 5 to 6 minutes. Remove from the steamer and set aside.
Heat 1 1/2 teaspoons oil in a nonstick skillet over medium-high heat. Add tuna and saute until the flesh is opaque, 3 to 5 minutes. Spoon tuna over potato mixture. Add the remaining 1 1/2 teaspoons oil to the pan. Add garlic and anchovies and cook, stirring, for 30 seconds. Add remaining 3 tablespoons vinegar and broth. Bring to a boil, stirring, and boil for 1 to 2 minutes. Stir in mustard. Spoon over the potato mixture. Add green beans, red peppers, capers and lemon juice and toss gently. Taste and adjust seasonings.
To oven-roast peppers:
1. Preheat oven to 450°F. Place a wire rack on a large baking sheet. Arrange whole bell peppers on the rack.
2. Roast peppers in the center of the oven, turning occasionally with tongs, until blackened in places, 30 to 40 minutes.
3. Transfer the peppers to a large bowl and cover with plastic wrap. Let steam for 10 minutes. Uncover and let cool.
4. With a paring knife, remove stems, skins and seeds. If serving as antipasto, combine accumulated juices with peppers.