hikiniku wo itameru toki ha, huta wo sita mama de ha umaku itamerarenai.

The は turns 炒めるとき (when frying / when you fry) into the topic of the sentence.

So:

• ひき肉を炒めるとき = when frying ground meat
• ひき肉を炒めるときは = as for when frying ground meat...

It gives the sentence an instructional, general-rule feeling, like:

• When frying ground meat, ...
• As for frying ground meat, ...

This is very common in explanations, recipes, and advice.

Because ひき肉 is the direct object of 炒める.

• ひき肉 = ground meat / minced meat
• を = marks what the action is done to
• 炒める = to fry / sauté / stir-fry

So:

• ひき肉を炒める = to fry ground meat

This is just standard object marking.

Here とき means when in a general situation.

• 炒めるとき = when frying
• in this sentence, it means something like when you are frying ground meat or when frying ground meat

It is not really an if sentence by itself. The sentence is giving advice about a situation that happens during cooking.

So the overall feeling is:

• When frying ground meat, you can't do it well if...

フタをする is a set expression meaning to put a lid on or to cover with a lid.

So:

• フタ = lid
• フタをする = to put the lid on
• フタをした = having put the lid on / with the lid on

Here した is the plain past form, but it is not mainly talking about past time. It is modifying まま and describing a resulting state:

• フタをしたまま = with the lid left on

So this does not mean "put the lid on and then, in the past...". It means the state after putting the lid on remains unchanged.

まま means while remaining in that state or without changing that condition.

So:

• フタをしたまま = with the lid still on
• literally, something like in the state of having put the lid on

This pattern is very common:

• 靴をはいたまま = with shoes still on
• 電気をつけたまま = with the light left on
• 窓を開けたまま = with the window left open

In your sentence, it means the meat is being fried without removing the lid.

ままでは adds the sense of if you leave it in that state or in that state, ... not.

Compare:

• フタをしたまま = with the lid on
• フタをしたままで = with the lid on, and...
• フタをしたままでは = if you keep the lid on / with the lid on, then...

So in this sentence:

• フタをしたままではうまく炒められない
• If you keep the lid on, you can't fry it well

The では gives it a stronger conditional/logical connection.

Because the sentence means cannot fry it well, not do not fry it well.

• 炒めない = do not fry / will not fry
• 炒められない = cannot fry

Here 炒められる is the potential form of 炒める:

• 炒める = to fry
• 炒められる = can fry
• 炒められない = cannot fry

So:

• うまく炒められない = cannot fry it properly / cannot sauté it well

Even though -られる can also be passive, here the meaning is clearly potential because of the context.

Not exactly. うまく here means well, properly, or successfully.

It is the adverb form of うまい.

So:

• うまく炒められない = cannot fry it well
• more naturally: it won’t cook properly or you can’t brown it properly

In cooking, this often means the result is not right—for example, the meat may steam instead of browning.

So うまく is about doing the action successfully, not just about taste.

The subject is omitted, which is very normal in Japanese.

Depending on context, it could mean:

• you can't fry it well
• one can't fry it well
• it can't be fried well

In English, a natural translation in a recipe or cooking tip is often:

• You can’t fry it well with the lid on
• or It won’t fry properly with the lid on

Japanese often leaves the subject unstated when it is obvious from context.

No. 炒める means to fry in a pan, to sauté, or to stir-fry.

It is different from:

• 揚げる = to deep-fry

So in this sentence, the idea is frying ground meat in a pan, usually over medium or high heat, where browning matters. That is why keeping the lid on is a problem: moisture gets trapped and the meat does not fry properly.

Yes, it can also be written as 蓋.

• フタ = common, easy-to-read katakana spelling
• 蓋 = kanji form

In everyday Japanese, especially in recipes, instructions, packaging, and casual writing, katakana is often used for common household items and loanword-like everyday terms, even when a kanji exists.

So フタ is not unusual at all.

Yes.

• ひき肉 = hiragana spelling
• 挽き肉 = kanji + hiragana spelling

Both mean ground meat or minced meat.

Recipes often use hiragana because it is easier to read quickly, and many cooking terms are commonly written that way.

Yes, but the nuance would be a little different.

• 炒めるときに = at the time of frying / when frying
• 炒めるときは = as for when frying / when it comes to frying

In a recipe tip or general instruction, ときは sounds more natural because it sets up a rule or point of advice.

So:

• 炒めるときは、... = When frying, ...
• good for giving guidance

If you used ときに, it would sound a bit more like simply locating the action in time, rather than introducing a general caution.