How do I divide a two-dimensional array item into items?

I have such an array

var recipe = [
     {
     "ingredients":["potato", "tomato", "salt/pepper"], 
     "step" : 1,
     },
     {
     "ingredients":["Brendon Eich's hair", "pasta", "water/sauce"], 
     "step" : 2,
     },
]

I want to get this

var recipe = [
     {
     "ingredients":["potato", "tomato", "salt", "pepper"], 
     "step" : 1,
     },
     {
     "ingredients":["Brendon Eich's hair", "pasta", "water", "sauce"], 
     "step" : 2,
     },
]

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pls help me 🙂