I threw a potluck party last week.

I asked the twomy Filipino guests to make macaroni salad and tomato sauce spaghetti beforehand.

Referring to people by nationality alone sounds a little odd and impersonal if they are your guests or friends.

IBack in March, we went out for lunch together and we talked about their homemade cooking there.

I was very curious about their cooking at the time because they said they use lots of condensed milk orand sugar forin their cooking.

As promised, they brought them two dishes, and we enjoyed their food and also my homemadlong with my own home cooking.

Their cooking was sweet, as I had expected, butand they were very good.

Writing "but" means you were not expecting it to be good.

I think I'll try to make Philippine -style macaroni salad soon.

I would appreciate it if you could fix my sentences to sound more natural even if you have to fix full sentences.

I asked the two Filipinos to make macaroni salad and spaghetti with tomato sauce spaghetti beforehand.

I was very curious about their cooking at the time because they said they use lots condensed milk orand sugar forin their cooking.

Their cooking was sweet as I expected, but they wereit was very good.

I think I'll try to make PhFilippineo style macaroni salad soon.

I asked the two Filipinos to make macaroni salad and spaghetti with tomato sauce spaghetti beforehand.

Tomato sauce spaghetti sounds a little unusual to me (I’ve never heard it like that, but then again I also only really know about spaghetti bolognaise or spaghetti and meatballs so take this with a grain of salt).

In March, we went out for lunch together and we talked about their homemade cooking there.

I think “there” is a little unnecessary here.

I might also specify that you asked them to make those dishes because of this.
To do that I might delete this sentence. So I would probably say something like
“I asked the two Filipinos to make macaroni salad and tomato sauce spaghetti beforehand, as I was very curious about their use of condensed milk and sugar in their cooking following our meeting in March.”
Or otherwise you could also delete “following our meeting in March” and say something about having met up with them in March, where you talked about your differing cooking styles.

I was very curious about their cooking at the time because they said they use lots of condensed milk orand sugar forin their cooking.

When you say “lots” you usually say that there’s “lots of” something, so lots —> lots of.
The “or” made it sound a little like you were unsure of whether they had said condensed milk or sugar, or at least that’s what I thought.

The “at the time” part makes sense but the placement of it sounds a little confusing to me.

As promised, they brought them, and we enjoyed both their food and also my homemade cooking.¶
OR¶
As promised, they brought them, and we enjoyed their food and my cooking too.

In addition to my two above corrections, you could replace “also” in the original sentence with “alongside” or “along with”.

This is purely for naturalness.

Their cooking was sweet as I expected, but they wereit was very good.

I think “I” is unnecessary there, but it doesn’t really matter.
They were —> it was (cooking is singular, so you would use “was” like you did earlier in the sentence. If you still wanted to say it as “they were” then I would specify that you’re talking about the dishes (as in “but the dishes were very good”).
You could also add in “also” to say “…but it was also very good”

I think I'll try to make some Philippine style macaroni salad soon.

You could change “to make” to “making”.

I asked the two Filipinos to make macaroni salad and spaghetti with tomato sauce spaghetti beforehand.

In March, we went out for lunch together and w. We talked about their homemade cooking from there.

I'm assuming that you're talking about their homemade cooking from the potluck party. I'm unsure what you mean when you talk about their homemade cooking. I'm also unsure who you went out with for lunch in March. Did you eat lunch with the 2 Filipinos and the 2 Japanese people? I'm confused.

I was very curious about their cooking at the time because they said they use lots condensed milk or sugar for their cooking.

I'm guessing you're referring to the two Filipinos, but correct me if I'm wrong.

As promised, they brought them, and wir homemade food. We enjoyed both their food and also my homemade cfookingd.

What did you cook?

Their cooking was sweet as I expected, but they were very good.

I'm assuming it's the Filipino macaroni salad. Filipino spaghetti is also sweet.

I think I'll try to make PhFilippine styleo macaroni salad soon.

It's more natural to say Filipino in this case. Here's a Reddit thread discussing when to use Filipino vs Philippine: https://www.reddit.com/r/EnglishLearning/comments/58s0iu/whats_the_difference_between_philippine_and/

I would appreciate it if you could fix my sentences to sound more natural, even if you have to fix full sentences.

I was very curious about their cooking at theat time because they said they use a lots of condensed milk orand sugar for their cooking.

Their cooking was sweet as I expected, butand they were very good.

i will change it to 'and' to make it more convincing.

I think I'll try to mak'm looking forward to making some Philippine -style macaroni salad soon.

i will change the sentence, so that it will sound more natural :)

I invited two Filipinos and two Japanese people.

Before the party, I asked the two Filipinos to make macaroni salad and tomato sauce spaghetti beforehand.

In March, we went out for lunch together and we talked about their homemade cooking thernative cuisine.

At the time, I was very curious about their cooking at the time because they said they use lots condensed milk or sugar forin their cooking.

As promised, they brought them, and we enjoyed their food and also my homemade cookingdishes.

Their cooking was sweet as I expected, but they wereit was very good.

I think I'll try to make a Philippine style macaroni salad soon.