Heat the oven to 200°F (or heat a warming drawer if you have one). Line a baking sheet with paper towels. Heat 5 Tbs. of the oil in a small (8-inch) nonstick omelet pan over medium-high heat until the oil bubbles right away when the edge of a tortilla is dipped into it. Using tongs and working with one tortilla at a time, fry the tortillas until golden brown on both sides, about 30 seconds per side. As each one finishes frying, briefly dangle the tortilla above the pan to allow some of the excess oil to drip back into the pan, and then transfer the tortilla to the paper-towel-lined baking sheet. Sprinkle each tortilla with a little salt while it’s still hot. As you fry, adjust the heat to keep the oil from getting too hot or cool, and if the pan goes dry, add more oil, 1 Tbs. at a time. When all the tortillas are fried, keep them warm in the oven
Heat the remaining 2 Tbs. oil in a 12-inch skillet over medium-high heat. Add the onion and cook, stirring often, until softened and lightly browned around the edges, about 3 minutes. Stir in the cumin and cook until fragrant, about 30 seconds. Add the beans, 1 tsp. salt, and 1 cup water. Working quickly, mash the beans with the back of a fork until most but not all of them are broken apart, and simmer until the beans look creamy and spreadable and much of the water has been absorbed, about 3 minutes. Stir in the chipotle Tabasco sauce and season to taste with more salt if needed.
To serve, spread each tortilla with about 1/3 cup of the beans, and top with the feta, tomato, radishes, and cilantro leaves.