Our meals have taken you south of the border, but now it's time to head south of the Equator with this flat iron steak inspired by the flavors of Argentina. Salsa criolla is an Argentine version of fresh salsa made with bell pepper, red onion, oregano, and a splash of red wine vinegar to bring the flavors together into a tart, tender mix. A garlic-flecked aioli provides a creamy counterpoint to the tender steak and roasted potatoes.
Mince garlic. Peel potatoes and cut into 1" dice. Stem, seed, and cut red and yellow bell peppers into ¼" dice. Peel and halve red onion. Cut halves into ¼” dice. Rinse steaks, pat dry, and season both sides with ½ tsp. salt and a pinch of pepper.
Roast the Potatoes
Place a large oven-safe pan over medium-high heat and melt butter. Add potatoes to hot pan and cook, while stirring, 1 minute. Cover, reduce heat to medium, and cook 5 minutes, stirring once halfway through. Uncover, place pan in oven, and roast 20-22 minutes, stirring halfway through, until golden brown and tender. Remove from oven, season to taste with salt and pepper, and set aside.
Make the Salsa Criolla
While potatoes cook, place a medium oven-safe pan over medium heat. Add 2 Tbsp. olive oil, half the garlic (reserve remaining for aioli), oregano, yellow and red peppers, onions, ¼ tsp. salt, and a pinch of pepper to hot pan. Stir and cook 1 minute. Cover and cook 3-5 minutes, or until vegetables are tender but slightly firm. Add vinegar (to taste) and cook an additional 2 minutes. Season with ¼ tsp. salt and a pinch of pepper. Remove salsa criolla to a plate and wipe pan clean.
Cook the Steaks
Place pan from previous step over medium-high heat. Add 1 tsp. olive oil to hot pan. Add steaks and sear on one side 3-4 minutes, or until a dark brown crust forms. Flip steaks and place pan in oven 5-7 minutes, or until steaks reach a minimum internal temperature of 145 degrees. Remove from oven and let rest at least 5 minutes.
Make the Aioli
While steaks cook, combine mayonnaise, remaining garlic, and a pinch of pepper in a small bowl. Set aside.
Plate the Dish
Place potatoes and salsa criolla on a plate. Slice steak if desired (see From the Chef section for tips), and serve on top of salsa. Serve with garlic aioli on the side.