Toasting raw rice in hot oil--some of it may even pop like popcorn--adds texture to this steak-and-rice salad.
Put 1 1/2 cups rice in a medium saucepan and cover with 2 inches water. Bring to a boil over high heat. Reduce heat to maintain a simmer, cover and cook until tender, about 25 minutes. Drain and rinse under cold water until cool.
Meanwhile, toast chiles in a medium skillet over medium-high heat, until fragrant and darkened in spots, 2 to 3 minutes. Transfer to a mortar or clean spice grinder and let cool, about 5 minutes. Coarsely grind the chiles.
Return the pan to medium-high heat. Add oil and the remaining 6 tablespoons rice. Cook, stirring constantly, until the rice is deeply toasted, about 3 minutes. Scrape onto a paper-towel-lined plate to drain and cool, then lightly crush in the mortar or with the bottom of a heavy pot. Wipe out the pan.
Season steak with salt. Return the pan to medium-high heat and add the steak. Cook, flipping once, until an instant-read thermometer registers 130 degrees F for medium-rare, 4 to 5 minutes per side. Transfer the steak to a clean cutting board and let cool completely, about 25 minutes. Dice the steak.
Combine lime juice, fish sauce, tomatoes and shallots in a large bowl with the boiled rice, steak and a pinch of the ground chiles.
Just before serving, fold in basil and mint. Sprinkle with the toasted rice and more ground chile to taste.
To make ahead: Prepare through Step 5 and refrigerate salad for up to 1 day. Store toasted rice airtight at room temperature.
Equipment: Mortar & pestle or spice grinder