TORONTO, June 4 (Reuters) - Hedge funds focused on commodities have generated strong returns in 2021 and investors long wary of such funds are now putting money into them, betting the recovery from the pandemic will charge demand for oil, gas and raw materials from metals to grains to sugar and coffee. While money has flooded into other commodity investments, hedge funds are a more surprising choice after years of outflows and closures of several high-profile firms. Among the funds notching big gains this year are those run by famed oil investor Pierre Andurand.