Check your avocado is ripe before starting this recipe (see cooking tip). Preheat the oven to 220C, fan-forced. Line an oven tray with baking paper. Crush or finely chop the garlic. Finely chop the onion. Drain and rinse the corn and beans. Coarsely grate the cheese.
Step 2 — Start soup
Heat 2 tsp olive oil in a large saucepan over medium heat. Cook the onion, stirring, for 3-4 mins until softened. Add the garlic and Tex-Mex seasoning and cook, stirring, for 1 min or until fragrant.
Step 3 — Simmer soup
Add the chipotle (if you prefer less heat, reduce the chipotle to taste), tomato passata, corn and beans and 375ml (1½ cups) water to the onion mixture and stir to combine, then bring to a simmer. Cook, stirring occasionally, for 10 mins or until slightly reduced and the flavour is developed. Stir in 1 tsp sugar. Taste, then season with salt and pepper.
Step 4 — Bake quesadillas
While the soup is cooking, put half the tortillas on the lined tray. Scatter over the cheese, then sandwich with the remaining tortillas. Bake for 10 mins or until the cheese is melted and the quesadillas are golden.
Step 5 — Make avocado salsa
Meanwhile, coarsely chop the avocado. Finely chop the spring onion. Combine 2 tsp olive oil and 1 tsp white wine vinegar in a bowl. Add the avocado and spring onion to the dressing and toss to coat. Season with salt and pepper.
Step 6 — Get ready to serve
Quarter the quesadillas. Divide the bean soup and avocado salsa among bowls. Serve with the quesadillas.