Peel and halve the red onion. Roughly chop half and thinly slice the other. Peel and roughly chop 3 cloves garlic. Trim, deseed, and chop the jalapeño.
Place a large skillet over medium heat with 1 tbsp olive oil. Add the chopped red onion, chopped garlic, and as much of the jalapeño as you’d like. Sprinkle with salt and cook until the onion is softened about 4 to 5 minutes.
Drain and rinse the black beans. Add the beans to the skillet along with the Mexican mole spice, 1 cup water, and ¼ tsp salt. Cook until the beans are hot, about 4 to 6 minutes.
Transfer the bean mixture to a food processor and pulse until paste forms, with some texture still visible.
Peel the orange with a knife, slice or chop the flesh, and add it to a large bowl. Halve the avocado, remove the pit, and slice the flesh. Add the sliced avocado to the bowl along with as much of the sliced red onion as you’d like, a pinch of salt, and 1 tbsp olive oil. Toss the citrus avocado salad well to combine.
Return the puréed black beans and half of the walnuts to the large skillet over medium heat. Cook, stirring frequently, until hot.
Press 1 tortilla into the beans and flip to coat. Once pliable, fold the tortilla into quarters. Divide the baby spinach (half the bag of baby spinach is for the Brussels Sprout Caesar) between plates and lay the hot enfrijolada on top. Continue with the remaining tortillas.
Top the mole enfrijoladas with any remaining black bean purée. Squeeze half the lime over the plates and cut the remaining half into wedges.
Sprinkle each plate with the remaining walnuts and serve the citrus avocado salad on the side. Serve with lime wedges.