Chalupas are Pueblas most popular street snack. If very small tortillas are not available, trim store-bought corn tortillas to size with a cookie cutter. Queso fresco is a nonmelting Mexican cheese. In the mountains of northern Puebla, tiny, thick-skinned tomatoes with intense flavor are prized for this salsa.
Heat oil in large skillet over medium-high heat. Carefully place several tortillas in oil. Cook, turning, until thoroughly heated but still pliable with chewy texture, but not brittle. Remove from heat, drain on paper towels and continue until all tortillas are used up.
To serve, top mini corn tortillas with Salsa de Jitomate and sprinkle of cheese. At a buffet, serve salsa in decorative bowl and allow guests to serve themselves.
Salsa de Jitomate
Heat heavy, ungreased skillet to medium-high heat. Flattening guajillo chiles with spatula, toast chiles 2 minutes per side until chiles change color and release aromas. Remove to bowl of hot water. Toast d’arbol chiles 30 seconds, and add to water. Soak chiles at least 30 minutes or up to several hours until soft.
Roast tomatoes and unpeeled garlic cloves until each is covered with black spots. Remove from heat, cut out tomato stem ends and transfer tomatoes to blender. Trim hard ends from garlic, peel and scoop into blender. Add chiles and enough water to facilitate blending, and purée until well blended.
Pour salsa into bowl, and stir in oregano and salt. Let sit at least 30 minutes for flavors to meld.