Evan was rather dubious of the premise that the 'soup' would be fine. Then again, he still wasn't convinced it was meant to start out with bits of green, two halves of a red onion and some carrots. Evan had never heard of a soup with those sort of ingredients. Then again, he had heard of leek and potato and Evan wasn't actually sure whether the green thing Ron had chopped was leek. It could've been. Evan had no idea what a leek looked like before it turned into leek soup. Still, it wasn't like Ron had any potatoes. Even Evan knew you couldn't replace a potato with an onion. That's why you had potato chips and onion rings.
"Can't," Evan said in a response to Ron's question rather than carrying on criticising Ron's cooking, since, quite honestly, Evan did not in any way know enough about cooking to criticise someone. At least not out loud. "Gotta revise for exams," he explained, taking a rather large gulp of his tea now that it had cooled down a bit. "But I'll have time in about two weeks?" Evan offered, because once his exams would finish, he'd be free until September.