Brook was among four England players to contribute half-centuries in a 8-400 Â total that the West Indies got nowhere near on Thursday.
Brook, who inherited an ODI side in disarray following a dreadful Champions Trophy that led to Jos Buttler's resignation as skipper in March, claimed a record-equalling five catches to complete a memorable day.
He said: "That was a pretty phenomenal performance from the boys. Nice to get the series under way in good fashion.
"I'm not concerned [about no-one converting their runs into centuries]. We got 400 runs! That is something we can look at and we've been speaking about. Four of us got 50-plus scores. If one of us kicks on, that's a complete performance."
West Indies were reduced to 5-79 in the 15th over and were all out for 162 in the 27th after medium-pacer Saqib Mahmood knocked over the top order and fast bowler Jamie Overton got hold of the tail.
England can clinch their first ODI bilateral series win since September 2023 on Sunday in Cardiff. The third and last match is on Tuesday at the Oval.
About all that England lost at Edgbaston was the toss.
Ben Duckett and Jamie Smith, who was opening for the first time, pounced on mediocre bowling to smash 64 runs within seven overs. By the end of the powerplay, England had rushed to 90 for the loss of only Smith.
Duckett made 60 off 48 balls, his sixth fifty in his last 12 innings, and Joe Root 57 in his 59th fifty. Brook added 58 as the scoring rate was pegged back in the middle overs.
But as a 400 total looked to fall out of reach, Jacob Bethell, brought back from the Indian Premier League, launched into the West Indies with 82 off 53, falling only in the last over.
England reached 400 for only the sixth time, and have still never lost from that vantage point.
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