Mojo de ajo is Spanish for "garlic sauce." In addition to flavoring the fajitas, the mojo can be made separately from this recipe and put to use in other crowd-pleasing dishes: Toss a few spoonfuls with grilled shrimp or drizzle it over baked snapper for another tasty dinner.
Warming a Tortilla: There is more than one way to warm a tortilla. For a charred version, turn a gas burner to high. Using tongs, heat a tortilla directly over the flame, flipping it often, until dark spots form on both sides. Another stove-top technique is to set a tortilla in a dry skillet and warm it over medium-high heat for about 10 seconds, turning the tortilla once. You can also use a microwave: Simply place a tortilla between damp paper towels, and heat in microwave for 30 seconds.