Heat a large saute pan on medium high heat. Saute your onions and garlic in olive oil for 2-3 minutes. Remove from heat.

Place your black beans in a microwave safe container and add the sauted onions and garlic. Add the diced chiles in adobo sauce to the mixture. Sprinkle in some dried basil and sea salt. Stir and microwave for 2 minutes. Then use a potato masher mash the warm bens to your desired consistency and return to the microwave for 1 minute.

Meanwhile take a paper towel and using the same saute pan wipe out any excess oil or browning from the onions. Spray with cooking oil and on high heat, toast your tortillas until crsipy anywhere from 5 to 10 minutes.

Assemble your tostadas by placing the beans on top of a tostada, sprinkle with feta, top with spinach, sliced cherry tomatoes, dollop of sour cream and sprinkle with more feta and salsa.