Dice bell pepper and onion; side aside. In another bowl, whisk together the eggs, milk, salt, and pepper. Set aside.
Heat a large skillet over medium heat. Add the chorizo and cook for about 8-10 minutes, breaking it up until fully cooked and slightly crispy.
Transfer the cooked chorizo to a paper towel-lined plate to drain excess grease, leaving about 1 tablespoon of fat in the pan.
Add the diced onion and bell pepper to the same skillet and sauté for 3-4 minutes until softened.
Add the minced garlic and cook for another 30 seconds until fragrant.
Pour the egg mixture into the skillet with the vegetables and cook, stirring gently, until the eggs are just set but still moist, about 3-4 minutes.
Fold the cooked chorizo back into the egg mixture and remove from heat.
Warm the tortillas in a dry skillet or microwave for about 20 seconds.
Assemble the tacos by dividing the chorizo-egg mixture among the tortillas.
Top with shredded cheese, fresh cilantro, and avocado slices.
Serve immediately with lime wedges and hot sauce if desired.