Heat 2 tsp vegetable oil in medium saucepan over medium-high heat. Add just half the onion and a pinch of salt and pepper and cook until softened and beginning to brown, 3 to 5 minutes. Stir in just 1 tsp chili powder, just 1 tsp cumin, lentils, and ¼ cup water. Cook, using back of fork to mash lentils until they start to stick together and become creamy, 1 to 2 minutes. Remove from heat, cover to keep warm, and set aside.

Combine remaining onion, orange, mixed greens, vinegar, avocado, 1 tbsp olive oil, and a pinch of salt and pepper in medium bowl and toss to coat. Set aside orange-avocado salad.

Warm tortillas, one at a time, in large nonstick skillet over medium heat until warm and pliable, about 1 minute per side. Lay tortillas on clean work surface. Divide lentil filling between tortillas and spread into even layer on one half of tortilla. Top with cheddar and fold tortillas in half. Heat 2 tsp vegetable oil in same skillet over medium heat. Add 3 tacos and cook until crispy, 3 to 5 minutes per side. Transfer to plate and repeat with remaining tacos and oil.

Divide orange-avocado salad and tacos dorados between serving plates. Serve with hot sauce. ¡Buen provecho!

For 4-serving meal, double all ingredients. You may need to cook in batches, in larger cooking vessels, or for longer cook times. Follow visual cues in 2-serving recipe.