Mince garlic. Peel potatoes and cut into 1" dice. Stem, seed, and cut red and yellow bell peppers into 1/4" dice. Peel and halve red onion. Cut halves into 1/4” dice. Rinse steaks, pat dry, and season both sides with 1/2 tsp. salt and a pinch of pepper.

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.

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, 1/4 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 1/4 tsp. salt and a pinch of pepper. Remove salsa criolla to a plate and wipe pan clean.

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.

While steaks cook, combine mayonnaise, remaining garlic, and a pinch of pepper in a small bowl. Set aside.

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.