Crack the eggs into a mixing bowl. Add the milk, chili powder, cumin, salt, and black pepper. Whisk until smooth and fully combined.
Heat olive oil or butter in a nonstick skillet over medium heat.
Add the diced onion and bell pepper. Sauté for 2–3 minutes until softened.
Stir in the jalapeño and diced tomato. Cook for another 2 minutes until the tomatoes begin to soften.
Pour the egg mixture into the skillet.
Let the eggs sit undisturbed for about 30 seconds, then gently stir with a spatula, folding the eggs slowly as they cook.
Continue cooking until the eggs are fluffy and fully set but still soft.
Remove from heat and sprinkle with fresh cilantro.
Serve immediately with warm tortillas, avocado, salsa, or beans.