The standard way would be: Tayo na at kumain (tayo) ng halo-halo. (“Tayo na” is “let's go now”. The second “tayo” may be omittted. “Some” is “mga”, but we only use it when we refer to a number of items. Since halo-halo is a singular item in this case, we omit the “some” in the translation.) Colloquial: Tena't kumain (tayo) ng halo-halo. (“Tena't” is a contraction of “tayo na at”) Modern colloquial: “Tara, kain tayo ng halo-halo”. (“Tara” is a corruption of “tayo na”. “Kain” is a colloquial way of saying “kumain” when expressed as an invitation to eat. The sentence translates to, “let's go, let's eat (some) halo-halo. This is almost the same as Sharmaine's translation, but I'd be more conservative and retain the linker, "ng".)

Tara kain tayo ng halo halo

Tara kain tayo halo halo