You have to cook 34 Fish and chips to obtain the first star, requiring 34 Guppies, 102 Potatoes and 3 hours and 24 minutes.
For the second star, you have to cook it 103 times, figuring in the + 100% Serving Reward from the first crop star, it requires a cumulative total of 69 Guppies, 207 Potatoes and 6 hours and 54 minutes. That is an additional 35 Guppies, 105 Potatoes on top of the first star, and an additional 3 hours and 30 minutes. Notice the cumulative numbers for the second star reflect cooking 104 Fish and chips since you can have to cook two recipes at time after the first recipe star reward.
The third star requires cooking 206 Fish and chips, figuring in the + 100% Serving Reward from the first crop star, it requires a cumulative total of 120 Guppies, 360 Potatoes and 12 hours. From the perspective of the first star, you need an additional, 86 Guppies, 258 Potatoes and 8 hours and 36 minutes. From the perspective of the second star, you need an additional 51 Guppies, 153 Potatoes and 5 hours and 6 minutes.