I marked points at the top left hand corner, that were 1.5cm and 3cm, and I drew a line from the 3cm mark down to the bottom right hand corner, and then measured up from that corner, up 7.5cm and drew a line from that point to the 1.5cm mark. This was the area that was cut away to give a peek at the recessed panel. The sentiment is using a Kaisercraft 'save the date' stamp set. I lined the two internal edges with a fine piece of pale blue card, and mounted them onto fun foam.
To make this I used the Altenew Peony Bouquet stamp set, and used the flower bud, the smaller leaves and the larger of the berries. I stamped them using the Altenew crisp inks in Buttercream, warm sunshine, Jet Black, Caramel toffee, frayed leaf, and then used a medium blue pigment ink cube, it doesn't have the brand on it sorry, and the Adirondack Denim dye ink.
Once that was stamped, I trimmed it to fit into my 'window' and glued it to my card base which is made of white linen card measuring 5 x 7inches.
I then decided it was a little plain just like that, so I stamped some more of the flowers and leaves, fussy cut them out, leaving a small white border, and then mounted them into a 'bouquet' with glue and foam tape, making sure to fill the area under the flowers and leaves, in the recess with foam tape, to support the 'bouquet'. Finally I used some Kaisercraft yellow droplets which I have had in my stash forever!
The supplies I have used in this card are:
Altenew Peony Bouquet stamp set
White linen card base 5 x 7 inches and a card panel the same size
Altenew crisp inks in Jet black, buttercream, warm sunshine, caramel toffee & frayed leaf
Medium blue pigment ink mini cube (sorry no idea of brand)
Adirondack Denim dye ink pad
Kaisercraft 'save the date' sentiment
Kaisercraft yellow 'droplets'
White fun foam
That completes the card, I hope this gives you some inspiration, you can really use any flower stamps to do this.