This easy-to-make classic Mexican casserole called sopa seca translates to "dry soup" in English, but it's not exactly a soup. It's more like a moist pasta casserole dish that's traditionally made with thin noodles, rice or even thin tortilla strips — and it's one of the most iconic dishes in Mexico.
Place the tomatoes, onion and garlic in a blender and puree until smooth, for about 2 minutes, adding a litter water if needed. Set aside.2.
In a saucepan, heat the oil over medium heat and add the fideo or vermicelli noodles. Cook the pasta, stirring frequently, until it is toasted and golden, about 5 to 7 minutes, being careful not to burn the noodles. Add the reserved tomato puree, and stir to combine well. Increase heat slightly and cook until the puree becomes darker, 3 to 4 minutes. Add 2 1/2 cups of water. Stir, bring to a boil, then reduce heat and allow to simmer, uncovered, until the pasta is cooked and all of the liquid is gone, about 15 minutes. Season with salt to taste.3.
To serve, divide the pasta among plates and garnish with avocado, queso, Mexican crema and diced Serrano chile.