This is a less-spicy version. For more heat, leave the serrano pepper seeds in and add red pepper flakes before or after cooking.
Cook the rice noodles according to directions, and set them aside.
Combine the sauce ingredients in a small bowl.
Heat a very large sauté pan with oil and brown the minced garlic. Add chiles and beaten eggs, and scramble in the pan until the eggs are in cooked bits.
Add onion and sliced beef and cook until beef is barely browned.
Add cooked noodles, tomatoes, chopped basil leaves, and sauce.
Keep stirring and combining until everything is saucy and hot. Serve immediately.