Rub the rim of a tall glass with a wedge of lime, then dip it into fine sea salt (Maldon smoked salt would be awesome here).
Halve the tomato and grate the cut side on a box grater into a perfumed slurry, discarding the skin and seeds.
Pour into the glass, along with the tequila. Squeeze in the juice from your lime wedge, add a dash of hot chilli sauce, and stir. Drop in a few chunky ice cubes, then top up the glass with cold lager.