In order to make full use of the efficiency of the pot and minimize the time, you can fry two fish at the same time. Because it takes 4 minutes to fry 1 fish and 4 minutes to fry two fish at the same time, two fish can fry seven fish twice respectively, and the last fish can be fried with three fish.

The time of the first four fish is 2*4=8 (minutes).

The last three fish put two fish in the pot at the same time. After 2 minutes, one is served, the other is turned over, and the third cake is put at the same time. Fry for another 2 minutes, the fish released for the first time can be cooked, and the fish released at last can be turned over and put down at the same time. In two minutes, all three fish will be cooked.

The time of the last three fish is 3*2=6 (minutes).

So it takes at least 14 minutes to fry seven fish.

Extended data:

This kind of problem belongs to pancake problem in mathematics, and the formula of pancake problem is:

Total time = number of cakes × 2÷ quantity per pot × time for baking each surface.

When the time is not an integer, approximate it with the method of entering one.

For example, when the number of cakes is 4, each pot is 3, and each side is baked for 2 minutes, according to the formula, 4×2÷3×2≈6 points.

When a pot can only bake two cakes: total time = time to bake one side × number of cakes.