a) Preheat your oven to 220°C/200°C fan/gas mark 7. Halve the peppers and discard the core and seeds. Slice into thin strips
b) Put the peppers on a baking tray, then drizzle with oil and season with salt and pepper. Toss to coat, then spread out.
c) Roast on the top shelf of your oven until soft and slightly charred, 12-15 mins. Turn halfway through.

a) Meanwhile, drain and rinse the kidney beans in a sieve.
b) Grate the cheese.

a) Heat a drizzle of oil in a frying pan on medium-high heat.
b) When hot, add the beans and Mexican style spice mix. Cook, stirring, for 1 min, then stir in the chopped tomatoes and vegetable stock paste.
c) Bring to the boil, then reduce the heat to medium and simmer, stirring occasionally, until thickened, 7-8 mins.

a) Halfway through the peppers' cooking time, lay the tortillas onto a lightly-oiled baking tray in a single layer and drizzle with oil.
b) Season with salt and pepper, then bake on the middle shelf of the oven until golden and crispy, 4-6 mins.

a) Zest the lime and chop into wedges.
b) Pop the soured cream in a small bowl. Mix in the lime zest and season to taste with salt and pepper.

a) Taste the bean mixture and season if needed.
b) Top the crisp tostadas (3 per person) with spoonfuls of the veggie bean mix, roasted peppers and cheese - as much as you'd like.
c) Finish with a dollop of zesty soured cream. TIP: Tostadas are best enjoyed eaten by hand - get stuck in!
d) Serve with the lime wedges for squeezing over. Enjoy!