Jax vs Cho'Gath

Start your trades with Counter Strike (E): you dodge autos and take less area damage, and each dodged auto adds damage to the stunning counterattack.

Look for long trades: each consecutive auto increases your attack speed thanks to Relentless Assault (passive).

To escape, place a ward and jump to it with Leap Strike (Q): it can target any unit or ward, allied or enemy.

Activate Grandmaster-at-Arms (R) up close: it only grants armor and magic resist if it hits a champion, and your bonus hits then land every other auto.

Keep moving against him: Rupture (Q) strikes an area on the ground, and an enemy standing still takes a knock-up, damage and a slow.

Punish him when he goes for last hits: Carnivore (passive) restores health and mana for each unit he kills, and he lasts a long time in lane if you let him farm.

If you have range, keep your distance: his kit has no dash, only the slows from Rupture (Q) and Vorpal Spikes (E).

Don't stay in melee range at low health when Feast (R) is up: its true damage ignores your resistances, even if you're a tank.