Step 1

Preheat oven to 250°. Toss 1 large tomato, finely chopped, ½ small white onion, finely chopped, 1 jalapeño, finely chopped, and ½ cup finely chopped cilantro in a medium bowl to combine. Add juice of ½ lime and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt and toss again to coat. Set pico de gallo aside.

Step 2

Heat 1 Tbsp. extra-virgin olive oil in a large skillet over medium-high. Add 1 lb. ground beef, 1½ tsp. ground cumin, 1 tsp. ground coriander, ½ tsp. smoked paprika, ¼ tsp. cayenne pepper, and remaining 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt and cook, stirring often and breaking meat up with a wooden spoon or heatproof rubber spatula, until meat is browned and nearly cooked through, about 3 minutes.

Step 3

Add 2 garlic cloves, thinly sliced, and 2 Tbsp. tomato paste to pan and cook, stirring occasionally, until combined, about 2 minutes. Add 2 Tbsp. water and cook, stirring occasionally, until incorporated, about 1 minute.

Step 4

Meanwhile, heat two 16-oz. cans refried beans in a medium saucepan over medium, stirring occasionally, until heated through, about 4 minutes.

Step 5

Arrange 8 tostadas in a single layer on a baking sheet and bake until just heated through, about 4 minutes. Remove from oven and top each tostada with a layer of refried beans, a scoop of beef mixture, and a spoonful of reserved pico de gallo. Divide 1 avocado, thinly sliced, and ¼ cup crumbled Cotija cheese over.