In a large bowl, place steak and next 4 ingredients (chili powder through oregano). Add sea salt and freshly ground black pepper to taste. Toss steak until evenly coated.
In a large skillet over medium-high heat, melt coconut oil. Add steak to pan in a single layer. Let sear for 3 to 4 minutes. Flip steak over and sear other side for 3 to 4 minutes. Remove steak from skillet and set aside.
Add next 5 ingredients (yellow bell pepper through mushrooms) to skillet. (If pan is getting too dry, add1/4 cup of vegetable broth.) Scrape brown bits from pan and toss veggies for 3 to 5 minutes, until they begin to soften.
Add green onion, jalapeño, vegetable broth, steak and any juices that collected under steak. Toss and cook for 5 to 8 minutes.
Remove from heat and serve warm on lettuce leaves topped with avocado and cilantro.