Prepare ingredients: Pat the 10 oz skirt steak dry with paper towels and season both sides with 1/2 teaspoon salt, 1/4 teaspoon black pepper, and 1 teaspoon chili powder. Slice the red and green bell peppers into 1/2" strips, thinly slice 1/2 red onion, chop 6 cups romaine/leaf lettuce, and zest then juice 1 lime. Cut avocado in half, remove pit, and set aside to make guacamole.

Bring the steak to room temperature: remove the 10 oz skirt steak from the fridge and let sit for 10 minutes while you prep the vegetables. Pat it dry with paper towels.

Prep produce: core and thinly slice the red and green bell peppers into 1/4-inch strips (about 1 cup each). Finely slice 1/4 cup (about 2 tbsp) of the 1/2 red onion for the fajita peppers; reserve 2 tbsp finely minced red onion for the guacamole. Tear or roughly chop the 6 cups of romaine/leaf lettuce and place in a large bowl or on two serving plates.

Marinate briefly: In a small bowl combine 1 tablespoon olive oil and the lime juice (about 1 tablespoon). Brush or rub the mixture over both sides of the seasoned steak. Let rest at room temperature for 10 minutes while you preheat the pan. (This is a quick marinade to add brightness and prevent over-salting.)

Preheat skillet: Place a heavy skillet or cast-iron pan over medium-high heat until very hot — about 2–3 minutes. If you like extra char, increase to high for 30 seconds before adding steak.

Make the quick guacamole: Halve and pit the avocado, scoop the flesh into a small bowl and mash with a fork until slightly chunky. Add the reserved 2 tbsp minced red onion, the juice of 1/2 lime (about 1 tbsp), 1/4 tsp salt, 1/8 tsp black pepper and a pinch (about 1/4 tsp) of chili powder. Taste and adjust with a little more lime or salt if needed. Cover with plastic wrap pressed to the surface or set aside.

Sear the steak: Add the steak to the hot dry or very lightly oiled skillet (you already used the 1 tbsp olive oil for the marinade; add a quick spray or 1/2 tsp oil to the pan if it looks dry). Sear 3–4 minutes without moving for a good crust, flip and cook 3 more minutes for medium-rare (adjust 1–2 min per side for thinner or thicker steak). Internal temperature target: 125–130°F (rare-medium rare) to 135°F (medium).

Season the steak: sprinkle the skirt steak on both sides with 1/2 tsp salt, 1/4 tsp black pepper and 1 tsp chili powder. Squeeze the juice of the remaining 1/2 lime over the steak and rub the seasoning in. Let sit 5–10 minutes while you heat the pan.

Rest and slice steak: Transfer steak to a cutting board and let rest for 5–7 minutes to reabsorb juices. Then slice very thinly against the grain into strips (~1/4" thick). While steak rests, proceed to cook peppers and onion.

Heat a large heavy skillet or cast-iron pan over medium-high heat until very hot (about 2–3 minutes). Add the 1 tbsp olive oil and swirl to coat the pan.

Sear the steak: place the steak in the hot pan and sear without moving for 2.5–3 minutes to develop a good crust. Flip and sear the other side 2–3 minutes for medium-rare (longer 3.5–4 minutes per side for medium). Internal temperature target: 125–130°F for medium-rare, 135°F for medium. Transfer steak to a cutting board and let rest 5 minutes (carryover will finish cooking).

Cook the peppers and onion: Return the skillet to medium-high (wipe out excess fat if there's a lot, leave fond for flavor). Add the sliced peppers and onion with a small pinch of salt (about 1/4 tsp) and a grind of black pepper. Sauté, stirring frequently, 5–7 minutes until edges are charred and vegetables are tender-crisp. If the pan becomes very dry, add 1/2 tsp olive oil.

While the steak rests, use the same hot pan (no need to add more oil unless the pan is dry—if dry, add a teaspoon) to cook the peppers and sliced onion. Add the pepper strips and the 1/4 cup sliced red onion, sprinkle with 1 tsp chili powder, 1/2 tsp salt and a pinch (1/8 tsp) black pepper. Sauté, stirring occasionally, until the edges are blistered and peppers are tender-crisp, 4–6 minutes.

Make the guacamole: In a bowl, mash the avocado with the lime zest and 1/2 tablespoon lime juice, 1/4 teaspoon salt and a pinch of chili powder and black pepper to taste (about 1/8 tsp). Taste and adjust — add extra lime or salt if needed. The guacamole should be slightly chunky.

Assemble the salads (serves 2): Divide the 6 cups chopped lettuce between two plates or bowls (about 3 cups each). Top each bed of greens with half the sautéed peppers and onions, then arrange the sliced steak on top. Spoon half the guacamole (about 1/2 avocado each) onto each salad. Optional: squeeze any remaining lime over the salads and drizzle a little of the warm pan juices or 1/2 tsp olive oil per plate.

Slice the steak thin: cut the rested steak against the grain into 1/4-inch slices. This will maximize tenderness.

Finish and serve: Sprinkle an additional pinch of chili powder and a crack of black pepper over each salad if desired. Serve immediately while steak is warm. Enjoy!

Assemble the salad: divide the torn lettuce between two plates or bowls. Top each with half the warm pepper/onion mixture (about 1/2 of the peppers mixture per plate) and then arrange the sliced steak on top (about 5 oz steak per serving).

Finish and dress: spoon half of the guacamole (about 1/2 avocado each) onto each salad. If you like, squeeze a little extra lime over the assembled salad and finish with a small drizzle of olive oil or an extra pinch of chili powder for heat.

Serve immediately while steak and peppers are still warm. Optional: serve with warm tortillas or tortilla chips if desired (not included in calorie count).