When you got to the second part, did you restart to the first part after dying? The game is built so that when you get to the second part and died, you'd restart in the beginning of the second part. (Unless if you meant that you were trying to get the different endings each time, in which case, the cooking score is tied to the endings. We're making an update to the main game that'll make the cooking part less tedious if you don't care much for what ending you get, so look out for that)
Ahh, ok. Welp, once the main game update happens (should be soon, fingers crossed) instead of losing points when you fail a customer, you lose 30 seconds (the first half is 5 minutes). So, you'll basically only have to serve one customer right and fail the rest to get there quickly. There is also other quality of life changes for the first part that should improve the experience (and the tutorial will be updated accordingly).