Wissenschaft passt auch in dier Küche

Heston Blumenthal ist wahrscheinlich mein Lieblingskochef, er kocht mit Wissenschaft.

Never use "Chef" for the english "chef". In German "Chef" is one word for "boss" (the english word comes from the french "chef de cuisine" that means "head of cooking", German took the french "chef" correctly as "head of", it is related to english "chief"). There is a german "Chefkoch" as "head of the cooking department", so literally the french word.

Er entwickelt seine Rezepte auf der Suche nach molekularen Mustern, dass macht ihn zu einem Anhänger dereines relativ neuesn Feldes in der Gastronomie namens Molekulargastronomie.

There are a lot of cases that need to be observed and that makes it a relatively hard sentence. Even some Germans wouldn't use the cases correctly here.
The "dass" "das" difference is hard to explain (in english), some Germans still don't know the difference.

Ich mag seine Showsendung und habe ein bisschen von ihm gelernt.

Show in this context is entirely okay to use. Most younger people would only use that, but for sake of german-learning, Germans would use "Sendung".

Das scheint simpel, aber Heston erklärt dass es gibt eine besondere rReaktion namens "Maillard Reaction" die verleihtgibt, die dem Steak Geschmack und passiertverleiht und statt findet, wenn man es bei sehr hohen Temperaturen kochent.

In German, the verb in main sentences is always on the (grammatical) end. Only in secondary sentences the verb is at the second (grammtical) place. That makes long, nested sentences kind of complicated and hard for foreigners.

Ein paar Freunde haben einmal Eis mit Flüssigstickstoff gekochent, es war sehr lecker.

The same as above, third person singular of "kochen" is "kocht".