Preheat the oven to 180C / 360F.
Make the seasoning mix. Add the fennel seeds to a pestle and mortar and lightly crush them. Add the remaining spices and salt, then set aside.
1 tsp fennel seeds, 1 tsp chili powder, 1/2 tsp smoked paprika, 1 tsp ground cumin, 1 tsp dried oregano, 1/2 tsp ground coriander, 1/2 tsp salt, 1/2 tsp garlic powder
Lay the tortillas out across a couple of large baking sheets and brush or spray with oil on both sides. Place in the oven for 4 minutes until they are starting to crisp up.
10 corn tortillas
Remove from the oven and flip each tortilla over. Add a handful of cheese to the top of each tortilla and then place back in the oven for another 4 minutes or until the cheese is melted.
1 cup grated cheddar cheese
Meanwhile, add the chickpeas to a large bowl and use a potato masher to lightly smash them. You want some to be left whole while others are in smaller pieces - this creates the most interesting texture.
14 oz can of chickpeas
When the tortillas are done, remove from the oven and let them sit until the chickpeas are ready - as long as they stay on the baking tray, they will stay warm enough.
Heat a large saute or frying pan with a shallow layer of oil over a low/medium heat. Add the chickpeas and let them sit for 2 minutes in the pan, then mix them up, let them sit a little longer, and repeat the process until the chickpeas are just starting to turn a more golden color and the smaller pieces are getting crisp. This generally takes around 5 minutes for me, but different pans and heat levels may be faster or slower.
Add the seasoning mix to the pan with another glug of oil and cook for another couple of minutes until there are really defined crispy bits and the spices are well toasted. Make sure the heat is on the lower end for this - we don't want to burn the spices.
Assemble your tostadas. Spread a little guacamole over the cheesy tortilla, then spoon over the chickpeas. Add onion, cilantro and sour cream to taste and dive in !
1/2 cup guacamole, 4 tbsp sour cream or crema, 1 handful cilantro (fresh coriander), 2 tbsp red onion