Former NYer here, for straight coffee & breakfast sandwiches, my go to is THB (I go to the one in Canton but apparently there’s one in Charles Village as well). Mostly known for bagel sandwiches, but they do have decent Kaiser buns that should hit the spot. Might be more than $4 now though…darn inflation.

For sushi take-out, Mizu is awesome but for a sit down experience Sizka is pretty good.

Concur with the Pho Bac recommendations for Bahn Mi, though I haven’t had the tofu specifically.

For spicy udon soup, this might not be exactly what you want because it’s not technically udon soup at all but it’s so good I feel like I must mention it as a tangentially related food option: Mi & Yu Noodle Bar in Fed Hill is so so delicious.