Meal times!

Tbh my partner cooks dinner most days, but when I do, I usually just opt for something super simple so it doesn't take me more than 5-10 minutes to prep (say, pasta with some simple tomato/pesto sauce, maybe steamed side veg, and some salad), cause if it's more than that, I know my lo is going to end up either getting into some trouble where I can't see her or just start gettting impatient around the kitchen. I don't dislike cooking per se, but I've always been a bit impatient with it, so I usually cook like that anyway! But if you're stuck for inspiration, I believe Jamie Oliver published a book of 15 minute recipes.
Alternatively, you could do prep when your partner is home and just cook in the evening to cut time in the kitchen when you're alone.

Chicken nuggets in the air fryer is my meal for my little guy. 1 min oatmeal in the morning and milk to fill up the other spaces in his tummy!!

It does get better. I always used to cook extra... so the next lunch time or whatever we would have the leftovers. And anything even more extra would go in little pots for my little one in the freezer for really bad days where I just need to get her fed and I just want to go bed 😂
Also cans of soup... with veggies or meat cause everything is already chopped up small, mixed with rice. It was very easy and my little one liked it and still got a nutricious meal

Meal prepping really helps us. We also got a toddler tower and plop her in there and she has "jobs" to do.

My son in theory eats what we're having, only lately he turns his nose up at most of the things we offer him, cries and often scoops it out of the bowl or plate onto the floor. I''ve been deliberately trying to cook things I think he'll like or has taken well before and he still rejects it. I'm losing my mind, it's so disheartening trying your best and they just cry at you! Also because he isn't eating enough for dinner he's up loads in the night and breast milk really isn't filling enough for long enough! So I'm very tired as well!

I try and have pre prepped meals in the freezer for her then we cook for us once she’s in bed! Make spare for her to warm up

Cook on their nap and put them in a playpen to reheat the food.
Cook with them, give them mushrooms/ banana and a butter knife etc.