In a large skillet, heat 1 Tbsp. olive oil. Add diced onions, season with salt, and cook for 3 minutes.
Add minced garlic and continue to cook until fragrant, about 30 seconds.
Stir in beans. Season with cumin, chili powder, oregano, salt, and pepper. Cook until beans have softened (about 3-4 minutes), stirring occasionally.
Remove from heat. Use a fork to mash beans to desired consistency and set aside.
In a large skillet, heat remaining olive oil over medium-high heat. Break eggs into skillet, keeping yolks intact. Reduce heat to low and cook until whites are firm, then carefully flip each egg. Finish cooking to desired doneness.
To assemble the tacos, warm the tortillas and evenly divide and spread beans onto each tortilla. Top with cooked eggs and add diced tomatoes and green chiles. Sprinkle with cheese, add diced avocado, and squeeze fresh lemon juice over each taco.
Garnish with parsley or cilantro and serve.