By Stanley Widianto NUSA DUA, Indonesia (Reuters) -Russian Foreign Minister Sergei Lavrov will have his first close encounter with the fiercest critics of his country’s invasion of Ukraine at a G20 gathering in Indonesia that was getting under way on Thursday. The Russia-Ukraine conflict and a global food crisis blamed on the war are expected to be front and centre of the two-day foreign ministers’ meeting on the island of Bali. Thursday’s welcome dinner will be the first time President Vladimir Putin’s long-serving foreign minister Lavrov will be up close with the most vocal opponents of Mosc…